The most basal ankylosaurine dinosaur from the Albian–Cenomanian of China, with implications for the evolution of the tail club

Abstract: The tail club knob is a highly specialized structure thought to characterize a subgroup of the ankylosaurine ankylosaurians, and the oldest documented tail club knob in the fossil record occurred in the Campanian ankylosaurine Pinacosaurus. Here we report a new ankylosaurid Jinyunpelta sinensis, gen. et sp. nov., from the Albian–Cenomanian Liangtoutang Formation, Jinyun County, Zhejiang, China. This is the first definitive and the best preserved ankylosaurid dinosaur ever found in southern China. Jinyunpelta possesses unique cranial features differs from other ankylosaurs including two paranasal apertures level with and posterior to the external naris, a triangular fossa on the anterodorsal edge of the maxilla, an antorbital fossa in the junction between the maxilla, lacrimal and jugal, and an anterior process of the prearticular that lies ventral to the splenial. Our phylogenetic analysis suggests Jinyunpelta as the most basal ankylosaurine dinosaur. Jinyunpelta has a tail club with interlocking caudal vertebrae and a well-developed tail club knob, it represents the oldest and the most basal ankylosaurian known to have a well-developed tail club knob. The new discovery thus demonstrates that a large and highly modified tail club evolved at the base of the ankylosaurine ankylosaurs at least about 100 million years ago.


Lower limits of ornithischian dinosaur body size inferred from a new Upper Jurassic heterodontosaurid from North America

Abstract: The extremes of dinosaur body size have long fascinated scientists. The smallest (<1 m length) known dinosaurs are carnivorous saurischian theropods, and similarly diminutive herbivorous or omnivorous ornithischians (the other major group of dinosaurs) are unknown. We report a new ornithischian dinosaur, Fruitadens haagarorum, from the Late Jurassic of western North America that rivals the smallest theropods in size. The largest specimens of Fruitadens represent young adults in their fifth year of development and are estimated at just 65–75 cm in total body length and 0.5–0.75 kg body mass. They are thus the smallest known ornithischians. Fruitadens is a late-surviving member of the basal dinosaur clade Heterodontosauridae, and is the first member of this clade to be described from North America. The craniodental anatomy and diminutive body size of Fruitadens suggest that this taxon was an ecological generalist with an omnivorous diet, thus providing new insights into morphological and palaeoecological diversity within Dinosauria. Late-surviving (Late Jurassic and Early Cretaceous) heterodontosaurids are smaller and less ecologically specialized than Early (Late Triassic and Early Jurassic) heterodontosaurids, and this ecological generalization may account in part for the remarkable 100-million-year-long longevity of the clade.

ornithischian dinosaur
dinosaur body size
theropod


Bacteria or melanosomes? A geochemical analysis of micro-bodies on a tadpole from the Oligocene Enspel Formation of Germany

Abstract:
Many exceptionally preserved fossils have long been thought the product of preservation by bacterial autolithification, based largely upon the presence of, micronsized, spherical or elongate bodies on their surface. This has recently been challenged by studies of similar fossils which cite morphological and geochemical evidence that these structures could be fossilized melanosomes, melanin-containing organelles. We geochemically analysed a tadpole from the Oligocene Enspel Formation, Germany, which displays such spherical bodies on its surface. Pyrolysis gas chromatography mass spectroscopy (Py-GCMS) and Fourier transform infrared spectrometry (FTIR) indicate that the organic remains of the tadpole are original and are not the result of external contamination, shown by the different chemical compositions of the fossil and its enclosing matrix. Py-GCMS also demonstrates the presence of bacterial and plant biomarkers in the matrix but not the tadpole, suggesting that the spherical bodies are unlikely to be bacterial, and also that such fossils do not develop their dark colour from incorporating plant material, as has been suggested. X-ray absorption spectroscopy (XAS)
shows high levels of organically bound Zn(II) in the fossilized soft tissue, a metal known to chelate both eu-and pheomelanin. The zinc in the tadpole shows greater similarity to that bound in pheomelanized extant samples than to that in eumelanized ones. Though further geochemical analysis of both pure pheomelanin and bacterial samples is required to completely exclude a bacterial origin, these results are in line with a pheomelanic origin for the spherical bodies on the tadpole.

melanosome
geochemical analysis
oligocene enspel formation
x-ray absorption spectroscopy
xas


Comparing Dirichlet normal surface energy of tooth crowns, a new technique of molar shape quantification for dietary inference, with previous methods in isolation and in combination.

Abstract: Inferred dietary preference is a major component of paleoecologies of extinct primates. Molar occlusal shape correlates with diet in living mammals, so teeth are a potentially useful structure from which to reconstruct diet in extinct taxa. We assess the efficacy of Dirichlet normal energy (DNE) calculated for molar tooth surfaces for reflecting diet. We evaluate DNE, which uses changes in normal vectors to characterize curvature, by directly comparing this metric to metrics previously used in dietary inference. We also test whether combining methods improves diet reconstructions. The study sample consisted of 146 lower (mandibular) second molars belonging to 24 euarchontan taxa. Five shape quantification metrics were calculated on each molar: DNE, shearing quotient, shearing ratio, relief index, and orientation patch count rotated (OPCR). Statistical analyses were completed for each variable to assess effects of taxon and diet. Discriminant function analysis was used to assess ability of combinations of variables to predict diet. Values differ significantly by diets for all variables, although shearing ratios and OPCR do not distinguish statistically between insectivores and folivores or omnivores and frugivores. Combined analyses were much more effective at predicting diet than any metric alone. Alone, relief index and DNE were most effective at predicting diet. OPCR was the least effective alone but is still valuable as the only quantitative measure of surface complexity. Of all methods considered, DNE was the least methodologically sensitive, and its effectiveness suggests it will be a valuable tool for dietary reconstruction.


Hirnantian (latest Ordovician) bio- and chemostratigraphy of the Stirnas-18 core, western Latvia

Abstract: Integrated study of the uppermost Ordovician Porkuni Stage in the Stirnas-18 core, western Latvia, has revealed one of the most complete Hirnantian successions in the eastern Baltic region. The interval is characterized by two shallowing upwards depositional sequences that correspond to the Kuldiga and Saldus formations. The whole-rock carbon stable isotope curve indicates a long rising segment of the Hirnantian carbon isotope excursion, with the highest peak in the upper part of the Kuldiga Formation. The bioclast carbon and oxygen curves fit well with the whole-rock carbon data. Microand macrofossil data enabled seven combined associations to be distinguished within the Hirnantian strata. The early Porkuni fauna of the Spinachitina taugourdeaui Biozone, with pre-Hirnantian affinities, is succeeded by an interval with a HindellaCliftonia brachiopod association, a specific polychaete fauna, the chitinozoan Conochitina scabra, and the conodont Noixodontus girardeauensis. The middle part of the Kuldiga Formation is characterized by a low-diversity Dalmanella testudinaria brachiopod association, high diversity of scolecodonts, and the occurrence of the chitinozoan Lagenochitina prussica. From the middle part of the Kuldiga Formation the youngest occurrence yet known of the conodont Amorphognathus ordovicicus is reported. Also typical of the Kuldiga Formation is the occurrence of the trilobite Mucronaspis mucronata. The uppermost Hirnantian Saldus Formation contains no shelly fauna, but yields redeposited conodonts and at least partly indigenous chitinozoans and scolecodonts. Palaeontological criteria and stable isotope data enable correlation of the Stirnas section with other Hirnantian successions in the Baltic region and elsewhere.


Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans

Abstract: The Late Cretaceous (∼95–66 million years ago) western North American landmass of Laramidia displayed heightened non-marine vertebrate diversity and intracontinental regionalism relative to other latest Cretaceous Laurasian ecosystems. Processes generating these patterns during this interval remain poorly understood despite their presumed role in the diversification of many clades. Tyrannosauridae, a clade of large-bodied theropod dinosaurs restricted to the Late Cretaceous of Laramidia and Asia, represents an ideal group for investigating Laramidian patterns of evolution. We use new tyrannosaurid discoveries from Utah—including a new taxon which represents the geologically oldest member of the clade—to investigate the evolution and biogeography of Tyrannosauridae. These data suggest a Laramidian origin for Tyrannosauridae, and implicate sea-level related controls in the isolation, diversification, and dispersal of this and many other Late Cretaceous vertebrate clades.

late cretaceous
laramidia
tyrannosaurid
biogeography
genealogy


Rapid Recovery of Life at Ground Zero of the End Cretaceous Mass Extinction

Abstract: The Cretaceous-Paleogene (K-Pg) mass extinction eradicated 76% of species on Earth1,2. It was caused by the impact of an asteroid3,4 on the Yucatán carbonate platform in the southern Gulf of Mexico at 66.0 Ma5 which formed the Chicxulub impact crater6,7. Following the mass extinction, recovery of the global marine ecosystem, measured in terms of primary productivity, was geographically heterogeneous8, as export production in the Gulf of Mexico and North Atlantic/Tethys took 300 kyr to return to Late Cretaceous quantities, slower than most other regions8–11. Delayed recovery of marine productivity closer to the crater implies an impact-related environmental control, like toxic metal poisoning12, on recovery times. Conversely, if no such geographic pattern exists, the best explanation for the observed heterogeneity is ecological, based on trophic interactions13, species incumbency and competitive exclusion by opportunists14, and “chance”8,15,16. Importantly, this question has bearing on the inherent predictability (or lack thereof) of future patterns of recovery in modern anthropogenically perturbed ecosystems. If there is a relationship between the distance from the impact and the recovery of marine productivity, we would expect recovery rates to be slowest in the crater itself. Here, we present the first record of foraminifera, calcareous nannoplankton, trace fossils, and elemental abundance data from the first ~200 kyr of the Paleocene within the Chicxulub Crater. We show that life reappeared in the basin just years after the impact and a thriving, high-productivity ecosystem was established within 30 kyr, faster than many sites across the globe. This is a clear indication that proximity to the impact did not delay recovery and thus there was no impact-related environmental control on recovery. Ecological processes likely controlled the recovery of productivity after the K-Pg mass extinction and are therefore likely to be significant in the response of the ocean ecosystem to other rapid extinction events.


Convergence and functional evolution of longirostry in crocodylomorphs

Abstract: During the Mesozoic, Crocodylomorpha had a much higher taxonomic and morphological diversity than today. Members of one particularly successful clade, Thalattosuchia, are well‐known for being longirostrine: having long, slender snouts. It has generally been assumed that Thalattosuchia owed their success in part to the evolution of longirostry, leading to a feeding ecology similar to that of the living Indian gharial, Gavialis. Here, we compare form and function of the skulls of the thalattosuchian Pelagosaurus and Gavialis using digital reconstructions of the skull musculoskeletal anatomy and finite element models to show that they had different jaw muscle arrangements and biomechanical behaviour. Additionally, the relevance of feeding‐related mandibular traits linked to longirostry in the radiation of crocodylomorph clades was investigated by conducting an evolutionary rates analysis under the variable rates model. We find that, even though Pelagosaurus and Gavialis share similar patterns of stress distribution in their skulls, the former had lower mechanical resistance. This suggests that compared to Gavialis, Pelagosaurus was unable to process large, mechanically less tractable prey, instead operating as a specialized piscivore that fed on softer and smaller prey. Secondly, innovation of feeding strategies was achieved by rate acceleration of functional characters of the mandible, a key mechanism for the diversification of certain clades like thalattosuchians and eusuchians. Different rates of functional evolution suggest divergent diversification dynamics between teleosaurids and metriorhynchids in the Jurassic.

functional evolution
longirostry
snout
ecology


Rearfoot posture of Australopithecus sediba and the evolution of the hominin longitudinal arch

Abstract:
The longitudinal arch is one of the hallmarks of the human foot but its evolutionary history remains controversial due to the fragmentary nature of the fossil record. In modern humans, the presence of a longitudinal arch is reflected in the angular relationships among the major surfaces of the human talus and calcaneus complex, which is also known as the rearfoot. A complete talus and calcaneus of Australopithecus sediba provide the opportunity to evaluate rearfoot posture in an early hominin for the first time. Here I show that A. sediba is indistinguishable from extant African apes in the angular configuration of its rearfoot, which strongly suggests that it lacked a longitudinal arch. Inferences made from isolated fossils support the hypothesis that Australopithecus afarensis possessed an arched foot. However, tali attributed to temporally younger taxa like Australopithecus africanus and Homo floresiensis are more similar to those of A. sediba. The inferred absence of a longitudinal arch in A. sediba would be biomechanically consistent with prior suggestions of increased midtarsal mobility in this taxon. The morphological patterns in talus and calcaneus angular relationships among fossil hominins suggest that there was diversity in traits associated with the longitudinal arch in the Plio-Pleistocene.
The longitudinal arch of the human foot aids in propulsion and represents an energy-saving and shock-absorbing mechanism that is part of a suite of midfoot stabilizing morphologies associated with a commitment to terrestrial locomotion 1-3 . Great apes lack these specializations for terrestrial locomotion and instead have much more mobile feet that are more suited to vertical climbing and arboreality 4,5 . Whether or not early hominins possessed a modern human-like longitudinal arch is controversial, in large part because few of the relevant foot fossils have been recovered. Of the hominin species that do preserve the relevant morphology, Ardipithecus ramidus (4.4 Ma) possessed an abducted hallux, which precludes a modern human-like longitudinal arch 6 . Foot fossils attributed to A. afarensis are found at Afar Locality 333 at Hadar, Ethiopia 7,8 , although there is a talus and two phalanges associated with the A.L. 288-1 partial skeleton. The A. afarensis foot skeleton has a mix of some ape-like traits (e.g., long, curved phalanges), and several traits derived in the direction of modern humans (e.g., talocrural joint orthogonal to tibia, robust calcaneal tuber). Previous researchers have suggested that A. afarensis lacked a longitudinal arch based on prominent tuberosities on the lateral cuneiform (A.L. 333-79) and naviculars (A.L. 333-36, -47) 9-11 . However, Australopithecus afarensis (3.8-2.9 Ma) is now generally agreed to have had a longitudinal arch, as demonstrated most clearly in the morphology of a complete fourth metatarsal 2,8 (but see ref. 12 for an alternative view) and the attribution of the Laetoli fossil footprints (3.7 Ma) to this taxon 13, 14 .

australopithecus sediba
hominin
locomotion
rearfoot posture


Multivariate Analyses of Small Theropod Dinosaur Teeth and Implications for Paleoecological Turnover through Time

Abstract: Isolated small theropod teeth are abundant in vertebrate microfossil assemblages, and are frequently used in studies of species diversity in ancient ecosystems. However, determining the taxonomic affinities of these teeth is problematic due to an absence of associated diagnostic skeletal material. Species such as Dromaeosaurus albertensis, Richardoestesia gilmorei, and Saurornitholestes langstoni are known from skeletal remains that have been recovered exclusively from the Dinosaur Park Formation (Campanian). It is therefore likely that teeth from different formations widely disparate in age or geographic position are not referable to these species. Tooth taxa without any associated skeletal material, such as Paronychodon lacustris and Richardoestesia isosceles, have also been identified from multiple localities of disparate ages throughout the Late Cretaceous. To address this problem, a dataset of measurements of 1183 small theropod teeth (the most specimen-rich theropod tooth dataset ever constructed) from North America ranging in age from Santonian through Maastrichtian were analyzed using multivariate statistical methods: canonical variate analysis, pairwise discriminant function analysis, and multivariate analysis of variance. The results indicate that teeth referred to the same taxon from different formations are often quantitatively distinct. In contrast, isolated teeth found in time equivalent formations are not quantitatively distinguishable from each other. These results support the hypothesis that small theropod taxa, like other dinosaurs in the Late Cretaceous, tend to be exclusive to discrete host formations. The methods outlined have great potential for future studies of isolated teeth worldwide, and may be the most useful non-destructive technique known of extracting the most data possible from isolated and fragmentary specimens. The ability to accurately assess species diversity and turnover through time based on isolated teeth will help illuminate patterns of evolution and extinction in these groups and potentially others in greater detail than has previously been thought possible without more complete skeletal material.

theropod tooth
statistical method
future study
isolated tooth


Palaeolatitudinal distribution of lithologic indicators of climate in a palaeogeographic framework

Abstract: Abstract Whether the latitudinal distribution of climate-sensitive lithologies is stable through greenhouse and icehouse regimes remains unclear. Previous studies suggest that the palaeolatitudinal distribution of palaeoclimate indicators, including coals, evaporites, reefs and carbonates, has remained broadly similar since the Permian period, leading to the conclusion that atmospheric and oceanic circulation control their distribution rather than the latitudinal temperature gradient. Here we revisit a global-scale compilation of lithologic indicators of climate, including coals, evaporites and glacial deposits, back to the Devonian period. We test the sensitivity of their latitudinal distributions to the uneven distribution of continental areas through time and to global tectonic models, correct the latitudinal distributions of lithologies for sampling- and continental area-bias, and use statistical methods to fit these distributions with probability density functions and estimate their high-density latitudinal ranges with 50% and 95% confidence intervals. The results suggest that the palaeolatitudinal distributions of lithologies have changed through deep geological time, notably a pronounced poleward shift in the distribution of coals at the beginning of the Permian. The distribution of evaporites indicates a clearly bimodal distribution over the past ~400 Ma, except for Early Devonian, Early Carboniferous, the earliest Permian and Middle and Late Jurassic times. We discuss how the patterns indicated by these lithologies change through time in response to plate motion, orography, evolution and greenhouse/icehouse conditions. This study highlights that combining tectonic reconstructions with a comprehensive lithologic database and novel data analysis approaches provide insights into the nature and causes of shifting climatic zones through deep time.

indicator
evaporite
glacial deposit
palaeolatitudinal distribution


OLDEST PLACENTAL MAMMAL FROM SUB-SAHARAN AFRICA: EOCENE MICROBAT FROM TANZANIA -EVIDENCE FOR EARLY EVOLUTION OF SOPHISTICATED ECHOLOCATION

Abstract: A partial skeleton of a new fossil microbat, Tanzanycteris mannardi, is the oldest placental mammal found in sub-Saharan Africa. It came from early Lutetian (46 Ma) lake sediments in north-central Tanzania. T. mannardi has enlarged cochleae indicating it was capable of a highly derived form of echolocation. Modern bats sharing similar morphology are capable of precise navigation in dense forest undergrowth. The phylogenetic relationships of T. mannardi are unclear. It shares character states with Eocene Hassianycterididae, with extant Microchiroptera, and with Rhinolophoidea within Microchiroptera. T. mannardi is important in documenting early evolution of sophisticated bat echolocating abilities and demonstrating that Tanzanian crater lakes offer an opportunity for future discoveries of Eocene mammals from the African interior.


Paleobiology of Herbivorous Dinosaurs

Abstract: Herbivorous dinosaurs were abundant, species-rich components of Late Triassic–Cretaceous terrestrial ecosystems. Obligate high-fiber herbivory evolved independently on several occasions within Dinosauria, through the intermediary step of omnivory. Anatomical character complexes associated with this diet exhibit high levels of convergence and morphological disparity, and may have evolved by correlated progression. Dinosaur faunas changed markedly during the Mesozoic, from early faunas dominated by taxa with simple, uniform feeding mechanics to Cretaceous biomes including diverse sophisticated sympatric herbivores; the environmental and biological drivers causing these changes remain unclear. Isotopic, taphonomic, and anatomical evidence implies that niche partitioning reduced competition between sympatric herbivores, via morphological differentiation, dietary preferences, and habitat selection. Large body size in dinosaur herbivores is associated with low plant productivity, and gave these animals prominen...

herbivorous dinosaur
ecosystem
mesozoic
body size
sauropod


Evolution of parental incubation behaviour in dinosaurs cannot be inferred from clutch mass in birds

Abstract: A recent study proposed that incubation behaviour (i.e. type of parental care) in theropod dinosaurs can be inferred from an allometric analysis of clutch volume in extant birds. However, the study in question failed to account for factors known to affect egg and clutch size in living bird species. A new scaling analysis of avian clutch mass demonstrates that type of parental care cannot be distinguished by conventional allometry because of the confounding effects of phylogeny and hatchling maturity. Precociality of young but not paternal care in the theropod ancestors of birds is consistent with the available data.

incubation behaviour
clutch mass
parental care
extant bird
egg


ORIGIN, EVOLUTION AND CLASSIFICATION OF THE NEW SUPERORDER NEPIOMORPHIA (MOLLUSCA, BIVALVIA, LOWER PALAEOZOIC)

Abstract: Abstract:  A number of bivalve taxa defined in the past as ‘Cryptodonten’ by Neumayr, 1884 were grouped together in the high‐level taxon Palaeoconchae Neumayr, 1884. Cox (1969) noted that Palaeoconchae and Cryptodonta were synonymous and Newell (1969) used Cryptodonta as a subclass of bivalves. However, for the past 120 years, the Cryptodonta has been poorly conceptualized and the name was used for poorly understood genera or those lacking dentition. As used by Newell, Cryptodonta included taxa now placed in the subclasses Protobranchia Pelseneer and Autolamellibranchiata Grobben, and to the class Rostroconchia Pojeta, Runnegar, Morris and Newell. The bulk of Newell's use of Cryptodonta was made up of Silurian and Devonian taxa first described by Barrande (1881) from Bohemia; Newell placed these in the order Praecardioida Newell. In effect, Cryptodonta became a ‘wastebasket’ grouping for what, at the time, were poorly understood taxa. Many of the formerly poorly understood praecardioids are now better known and are herein placed in the new superorder Nepiomorphia. The Nepiomorphia contains two orders: (1) order Praecardioida that includes the families Slavidae Kříž, Cardiolidae Hoernes, Praecardiidae Hoernes and Buchiolidae Grimm; and (2) new order Antipleuroida that includes the families Stolidotidae fam. nov., Spanilidae fam. nov. and Antipleuridae Neumayr. The Nepiomorphia originated probably in the early Silurian as result of r‐selection progenesis. When the marine current system became re‐established after the late Ordovician glaciation and in the early Silurian, an at least temporary ventilation of the shallow waters by surface currents was renewed in higher latitudes of peri‐Gondwana and Siberia, producing acceptable sea‐bottom environments. Larvae were distributed by surface currents from the warm tropical regions of Laurentia and Baltica and were among the first benthic organisms to colonize the new environments. Temporary ventilation created frequent density‐independent catastrophic mortalities of early ontogenetic stages, with no competitors and with super‐abundant resources. During the Silurian and early Devonian, the Nepiomorphia underwent several diversifications in the recurring cephalopod limestone biofacies characteristic of peri‐Gondwana, and evolved infaunal, semi‐infaunal and epifaunal modes of life in several lineages. The Nepiomorphia most probably became extinct during the early Carboniferous and had no role in the future evolution of the Bivalvia.

new superorder nepiomorphia
bivalvia
phylogenetic remark
family cardiolidae


REEF RECOVERY FOLLOWING THE FRASNIAN–FAMENNIAN (LATE DEVONIAN) MASS EXTINCTION: EVIDENCE FROM THE DUGWAY RANGE, WEST-CENTRAL UTAH

Abstract: ABSTRACT The temporally extensive late Middle through Late Devonian biotic crisis involved at least three distinct peaks of elevated extinction intensity during an interval spanning ∼25 myr and resulted in the preferential elimination of certain shallow-marine, warm-water taxa, especially members of reef communities. By the end of the second peak, delimited by the Frasnian–Famennian (F–F) boundary, the stromatoporoids, members of the dominant constructor guild in mid-Paleozoic reefal ecosystems, had ceased building reefs in most parts of the world. The northern Dugway Range in west-central Utah, United States, however, represents one of the few locations globally where stromatoporoids continued reef building into the Famennian. Two measured sections there, which are constrained biostratigraphically using conodonts, indicate that the biohermal sequences occur within the middle Palmatolepis crepida biozone and are early Famennian in age. The post-F–F extinction Dugway reefal faunas are depauperate and dominated by labechiid and stylostromid stromatoporoids, as is characteristic of other early Famennian reefs. In this region, evidence for reefal development is episodic, with stromatoporoid-bearing units interbedded with peloidal and coated-grain carbonate units lacking evidence of reef construction. The stromatoporoid survivors, although fairly minor constituents of Frasnian reef communities, belong to long-ranging clades and may represent so-called extinction-resistant taxa that flourished, albeit locally in Laurentia, following the F–F mass extinction.

frasnian–famennian
dugway range
west-central utah
biotic crisis


Maiasaura, a model organism for extinct vertebrate population biology: a large sample statistical assessment of growth dynamics and survivorship

Abstract:
Abstract
 Fossil bone microanalyses reveal the ontogenetic histories of extinct tetrapods, but incomplete fossil records often result in small sample sets lacking statistical strength. In contrast, a histological sample of 50 tibiae of the hadrosaurid dinosaur Maiasaura peeblesorum allows predictions of annual growth and ecological interpretations based on more histologic data than any previous large sample study. Tibia length correlates well (R2 > 0.9) with diaphyseal circumference, cortical area, and bone wall thickness, thereby allowing longitudinal predictions of annual body size increases based on growth mark circumference measurements. With an avian level apposition rate of 86.4 µm/day, Maiasaura achieved over half of asymptotic tibia diaphyseal circumference within its first year. Mortality rate for the first year was 89.9% but a seven year period of peak performance followed, when survivorship (mean mortality rate = 12.7%) was highest. During the third year of life, Maiasaura attained 36% (x = 1260 kg) of asymptotic body mass, growth rate was decelerating (18.2 µm/day), cortical vascular orientation changed, and mortality rate briefly increased. These transitions may indicate onset of sexual maturity and corresponding reallocation of resources to reproduction. Skeletal maturity and senescence occurred after 8 years, at which point the mean mortality rate increased to 44.4%. Compared with Alligator, an extant relative, Maiasaura exhibits rapid cortical increase early in ontogeny, while Alligator cortical growth is much lower and protracted throughout ontogeny. Our life history synthesis of Maiasaura utilizes the largest histological sample size for any extinct tetrapod species thus far, demonstrating how large sample microanalyses strengthen paleobiological interpretations.

survivorship
growth rate
maiasaura
crocodylian


Longibelus gen. nov., a new Cretaceous coleoid genus linking Belemnoidea and early Decabrachia

Abstract: The phylogenetic origin and the timing of origination of the Decabrachia are controversial. This is due to a poor understanding of character complexes relating to the shell, which causes difficulties in establishing homologies among different taxa. One central problem concerns a clear differentiation between belemnoids and early spirulids. A comparative analysis of shell structures of well‐preserved specimens including types and new material of Cretaceous spirulids Groenlandibelus, Naefia and Cyrtobelus, as well as selected taxa of aulacocerid, belemnitid and diplobelid belemnoids, revealed a set of 14 characters. Seven characters (apical angle, chamber length, dorsal and ventral sutures, orientation of septa, direction of the dorsal part of the septal neck, primordial rostrum) are not or less diagnostic, whereas the seven remaining characters can be reliably used to distinguish between the Decabrachia on the one hand and Belemnitida and Aulacocerida on the other hand. These diagnostic characters are as follows: (1) presence/absence of a mural flap; (2) position of the siphuncle; (3) shape of the dorsal soft tissue attachment scar; (4) presence/absence of tabular nacre in the conotheca; (5) presence/absence of a rostrum proper; (6) presence/absence of a narrow rod‐like proostracum; and (7) presence/absence of a caecum. Diplobelida and ‘Naefia’ matsumotoi, however, exhibit a mosaic of decabrachian and belemnoid characters. Owing to striking differences between N. neogaiea, the type species of Naefia, and ‘N.’ matsumotoi, the new genus Longibelus has been erected. Besides a redescription of Longibelus (‘Naefia’) matsumotoi, we describe the first Maastrichtian occurrences of this species from Hokkaido (northern Japan) and Alaska. Among the type material of N. neogaiea from the Maastrichtian of Chile, we found one specimen that unambiguously belongs to Longibelus gen. nov. Similarly, two specimens from the Maastrichtian of Mexico previously determined as N. neogaiea also belong to the new genus. Also, we can reinterpret material from the Cenomanian of India as Longibelus gen. nov. New material from the Albian of India likewise assignable to Longibelus is described for the first time. Finally, we introduce the first records of coleoids from Zululand (South Africa). These specimens belong to Longibelus as do specimens from the Aptian of Caucasus (previously described as ‘Naefia’ kabanovi). A phylogenetic approach suggests that Longibelus gen. nov. is derived from diplobelid‐like belemnoids and gave rise for the Decabrachia or at least groenlandibelid spirulids. This strongly supports earlier ideas on a close relationship between Cretaceous Decabrachia and belemnites and simultaneously challenges opinions that Decabrachia originated in the Carboniferous.

coleoid
belemnoidea
diplobelida
northern japan
longibelus


Review of the El Soplao Amber Outcrop, Early Cretaceous of Cantabria, Spain

Abstract: El Soplao outcrop, an Early Cretaceous amber deposit recently discovered in northern Spain (Cantabria), has been shown to be the largest site of amber with arthropod inclusions that has been found in Spain so far. Relevant data provided herein for biogeochemistry of the amber, palynology, taphonomy and arthropod bioinclusions complement those previously published. This set of data suggests at least two botanical sources for the amber of El Soplao deposit. The ñrst (type A amber) strongly supports a source related to Cheirolepidiaceae, and the second (type B amber) shows non‐specific conifer biomarkers. Comparison of molecular composition of type A amber with Frenelopsis leaves (Cheirolepidiaceae) strongly suggests a biochemical affinity and a common botanical origin. A preliminary palynologlcal study indicates a regional high taxonomical diversity, mainly of pteridophyte spores and gymnosperm pollen grains. According to the preliminary palynologlcal data, the region was inhabited by conifer forests adapted to a dry season under a subtropical climate. The abundant charcoalified wood associated with the amber in the same beds is evidence of paleofires that most likely promoted both the resin production and an intensive erosion of the litter, and subsequent great accumulation of amber plus plant cuticles. In addition, for the first time in the fossil record, charcoalified plant fibers as bioinclusions in amber are reported. Other relevant taphonomic data are the exceptional presence of serpulids and bryozoans on the surfaces of some amber pieces indicating both a long exposure on marine or brackish‐water and a mixed assemblage of amber. Lastly, new findings of insect bioinclusions, some of them uncommon in the fossil record or showing remarkable adaptations, are reported. In conclusion, a documented scenario for the origin of the El Soplao amber outcrop is provided.


TEASING FOSSILS OUT OF SHALES WITH CAMERAS AND COMPUTERS

Abstract: Simple yet effective methods are available to enhance photographic images of low-contrast and lowrelief specimens, such as fossils in shales, without manipulating or retouching the photographs. By applying polarizing filters to camera and light-source(s) in a way analogous to crossing nicols in a petrographic microscope, dramatic results can be achieved where there is a difference in reflectance between fossil and matrix, as with many coalified fossils. For example, this method is ideal for bringing out the shiny films representing soft tissues of Middle Cambrian Burgess Shale fossils. It is also useful in reducing reflections and increasing contrast in specimens that cannot be immersed in liquid (e.g., the Lower Cambrian Chengjiang fauna). Plants and graptolites in shales are other examples of suitable objects for this method. In addition, the use of digital imaging now makes it very easy to use interference between two versions to bring out differences. In this way, images of the same object taken with and without crossed nicols can be contrasted, as well as different colour channels. The result may be a dramatic improvement in the definition of hard-to-see or hard-to-image structures.

photograph
filter
burgess shale fossil
liquid
polarised light


Neural spine elongation in dinosaurs: sailbacks or buffalo-backs?

Abstract: Several dinosaurs, notably Ouranosaurus and Spinosaurus, have vertebral columns marked by prominent arrays of elongated neural spines. Using pelycosaurian sailbacks like Dimetrodon as analogies, popular orthodoxy holds that the tall spines served as supporting struts for dorsal sails of purported thermoregulatory function, especially heat dissipation in tropical climates. It is argued here that the neural spines of Ouranosaurus, Spinosaurus, and several other long-spined dinosaurs favor bison-like humps rather than sails: 1) in functional morphology and relative elongation they are dissimilar to pelycosaur spines but homoplastically converge on the spines of high-withered ungulates; 2) the usefulness of a sail in thermoregulation has been exaggerated—in large tetrapods it would have been fairly efficient as a thermal amplifier but ineffective as a radiator; hence large sail-bearing dinosaurs in open tropical climates are improbable; 3) the insulation properties of humps favor gigantothermy, the most likely thermobiological model for large dinosaurs. Dinosaur humps are probable adaptations for: 1) energy storage, maintenance of gigantothermy, and heat-shielding in unshaded habitats; 2) long-distance migration from feeding to nesting grounds across terrains of variable productivity; and 3) lipid conservation for production of large clutches of eggs at the nesting site. Because sacral, caudal, or dorsal humps were relatively common traits among certain groups, the fashionably anorexic image of many large dinosaurs must be emended.

elongation
sailback
thermoregulation
neural spine


Effect of a Jurassic oceanic anoxic event on belemnite ecology and evolution

Abstract: Significance The Toarcian oceanic anoxic event (OAE; ∼183 million y ago) is marked by one of the largest carbon cycle perturbations in Earth history, rapid climate change, widespread ocean oxygen deficiency, and strong changes in marine ecosystems. The temporal links between increasing atmospheric pCO2, changes in ocean oxygen availability, and marine biotic response during this event are still poorly understood. Here we use isotopic analyses of calcite and organic matter from belemnites, marine predators of that time, to address their response to bottom water anoxia during the OAE. We infer that some belemnite taxa showed resilience to a strong reduction in ocean oxygen availability and occupied ecological niches in the Cleveland Basin (United Kingdom), enabling a strong evolutionary diversification after the event. The Toarcian oceanic anoxic event (T-OAE; ∼183 million y ago) is possibly the most extreme episode of widespread ocean oxygen deficiency in the Phanerozoic, coinciding with rapid atmospheric pCO2 increase and significant loss of biodiversity in marine faunas. The event is a unique past tipping point in the Earth system, where rapid and massive release of isotopically light carbon led to a major perturbation in the global carbon cycle as recorded in organic and inorganic C isotope records. Modern marine ecosystems are projected to experience major loss in biodiversity in response to enhanced ocean anoxia driven by anthropogenic release of greenhouse gases. Potential consequences of this anthropogenic forcing can be approximated by studying analog environmental perturbations in the past such as the T-OAE. Here we present to our knowledge the first organic carbon isotope record derived from the organic matrix in the calcite rostra of early Toarcian belemnites. We combine both organic and calcite carbon isotope analyses of individual specimens of these marine predators to obtain a refined reconstruction of the early Toarcian global exogenic carbon cycle perturbation and belemnite paleoecology. The organic carbon isotope data combined with measurements of oxygen isotope values from the same specimens allow for a more robust interpretation of the interplay between the global carbon cycle perturbation, environmental change, and biotic response during the T-OAE. We infer that belemnites adapted to environmental change by shifting their habitat from cold bottom waters to warm surface waters in response to expanded seafloor anoxia.

oceanic anoxic event
organic matter
belemnite taxa


Floral Assemblages and Patterns of Insect Herbivory during the Permian to Triassic of Northeastern Italy

Abstract: To discern the effect of the end-Permian (P-Tr) ecological crisis on land, interactions between plants and their insect herbivores were examined for four time intervals containing ten major floras from the Dolomites of northeastern Italy during a Permian–Triassic interval. These floras are: (i) the Kungurian Tregiovo Flora; (ii) the Wuchiapingian Bletterbach Flora; (iii) three Anisian floras; and (iv) five Ladinian floras. Derived plant–insect interactional data is based on 4242 plant specimens (1995 Permian, 2247 Triassic) allocated to 86 fossil taxa (32 Permian, 56 Triassic), representing lycophytes, sphenophytes, pteridophytes, pteridosperms, ginkgophytes, cycadophytes and coniferophytes from 37 million-year interval (23 m.yr. Permian, 14 m.yr. Triassic). Major Kungurian herbivorized plants were unaffiliated taxa and pteridosperms; later during the Wuchiapingian cycadophytes were predominantly consumed. For the Anisian, pteridosperms and cycadophytes were preferentially consumed, and subordinately pteridophytes, lycophytes and conifers. Ladinian herbivores overwhelming targeted pteridosperms and subordinately cycadophytes and conifers. Throughout the interval the percentage of insect-damaged leaves in bulk floras, as a proportion of total leaves examined, varied from 3.6% for the Kungurian (N = 464 leaves), 1.95% for the Wuchiapingian (N = 1531), 11.65% for the pooled Anisian (N = 1324), to 10.72% for the pooled Ladinian (N = 923), documenting an overall herbivory rise. The percentage of generalized consumption, equivalent to external foliage feeding, consistently exceeded the level of specialized consumption from internal feeding. Generalized damage ranged from 73.6% (Kungurian) of all feeding damage, to 79% (Wuchiapingian), 65.5% (pooled Anisian) and 73.2% (pooled Ladinian). Generalized-to-specialized ratios show minimal change through the interval, although herbivore component community structure (herbivore species feeding on a single plant-host species) increasingly was partitioned from Wuchiapingian to Ladinian. The Paleozoic plant with the richest herbivore component community, the coniferophyte Pseudovoltzia liebeana, harbored four damage types (DTs), whereas its Triassic parallel, the pteridosperm Scytophyllum bergeri housed 11 DTs, almost four times that of P. liebeana. Although generalized DTs of P. liebeana were similar to S. bergeri, there was expansion of Triassic specialized feeding types, including leaf mining. Permian–Triassic generalized herbivory remained relatively constant, but specialized herbivores more finely partitioned plant-host tissues via new feeding modes, especially in the Anisian. Insect-damaged leaf percentages for Dolomites Kungurian and Wuchiapingian floras were similar to those of lower Permian, north-central Texas, but only one-third that of southeastern Brazil. Global herbivore patterns for Early Triassic plant–insect interactions remain unknown.


New Data on the Moschidae (Mammalia, Ruminantia) from the Upper Miocene of Spain (MN 10- MN 11)

Abstract:
ABSTRACT
 New data on the last representatives of the Spanish Miocene Moschidae (Mammalia, Ruminantia) are presented and discussed. A new species of Micromeryx, Micromeryx soriae, is described on the basis of fossil material from the locality of La Roma-2 (upper Vallesian; MN 10, Teruel province, Spain, previously assigned to Micromeryx sp.), Batallones-1, and Batallones-10 (upper Vallesian; local zone J, MN 10, Madrid province, Spain). The new species is characterized by possessing relatively hypsodont lower molars of advanced morphology and a unique type of Palaeomeryx-fold. M. soriae gives insight to the last representatives of the genus, which achieved an overall lower molar morphology that mimics to certain degree that of Hispanomeryx. several characters of the upper molars of the Miocene moschids Micromeryx and Hispanomeryx are described that are useful for characterizing both genera. These characters are used to solve the taxonomic problems of PM-659, an upper molar from Puente Minero (MN 11, Teruel province, Spain) that represents one of the last survivors of the Moschidae in the Iberian Peninsula. The systematic utility of the upper molars of Hispanomeryx and Micromeryx is demonstrated, and the use of size as the only way to distinguish between the two genera is refuted. Finally, the study of the morphological characters of PM-659 clearly supports its generic change from Micromeryx sp. to Hispanomeryx sp., thus recording the presence of Hispanomeryx in the Iberian Peninsula as late as the lower Turolian.

moschidae
mammalia
hispanomeryx
evolutionary history


Evolving between land and water: key questions on the emergence and history of the Hippopotamidae (Hippopotamoidea, Cetancodonta, Cetartiodactyla)

Abstract: The fossil record of the Hippopotamidae can shed light on three major issues in mammalian evolution. First, as the Hippopotamidae are the extant sister group of Cetacea, gaining a better understanding of the origin of the Hippopotamidae and of their Paleogene ancestors will be instrumental in clarifying phylogenetic relationships within Cetartiodactyla. Unfortunately, the data relevant to hippopotamid origins have generally been ignored in phylogenetic analyses of cetartiodactyls. In order to obtain better resolution, future analyses should consider hypotheses of hippopotamid Paleogene relationships. Notably, an emergence of the Hippopotamidae from within anthracotheriids has received growing support, leading to reconciliation between genetic and morphological evidence for the clade Cetancodonta (Hippopotamidae + Cetacea). Secondly, full account needs to be taken of the Hippopotamidae when studying the impact of environmental change on faunal evolution. This group of semi‐aquatic large herbivores has a clear and distinct ecological role and a diverse and abundant fossil record, particularly in the African Neogene. We examine three major phases of hippopotamid evolution, namely the sudden appearance of hippopotamines in the late Miocene (the “Hippopotamine Event”), the subsequent rampant endemism in African basins, and the Pleistocene expansion of Hippopotamus. Each may have been influenced by multiple factors, including: late Miocene grass expansion, African hydrographical network disruption, and a unique set of adaptations that allowed Hippopotamus to respond efficiently to early Pleistocene environmental change. Thirdly, the fossil record of the Hippopotamidae documents the independent emergence of adaptive character complexes in relation to semiaquatic habits and in response to insular isolation. The semiaquatic specializations of fossil hippopotamids are particularly useful in interpreting the functional morphology and ecology of other, extinct groups of large semiaquatic herbivores. Hippopotamids can also serve as models to elucidate the evolutionary dynamics of island mammals.

emergence
hippopotamidae
cetartiodactyla
phylogenetic relationship


The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future

Abstract: During the Paleocene-Eocene Thermal Maximum (PETM), ∼56 Mya, thousands of petagrams of carbon were released into the ocean-atmosphere system with attendant changes in the carbon cycle, climate, ocean chem- istry, and marine and continental ecosystems. The period of carbon release is thought to have lasted <20 ka, the duration of the whole event was ∼200 ka, and the global temperature increase was 5-8 ◦ C. Terrestrial and marine or- ganisms experienced large shifts in geographic ranges, rapid evolution, and changes in trophic ecology, but few groups suffered major extinctions with the exception of benthic foraminifera. The PETM provides valuable insights into the carbon cycle, climate system, and biotic responses to environmental change that are relevant to long-term future global changes.

paleocene-eocene thermal maximum
carbon cycle
carbonate
petm
ecosystem


Convergent Evidence of Eagle Talons Used by Late Neanderthals in Europe: A Further Assessment on Symbolism

Abstract: To contribute to have a better understanding of the symbolic or not use of certain items by Neanderthals, this work presents new evidence of the deliberate removal of raptor claws occurred in Mediterranean Europe during the recent phases of the Mousterian. Rio Secco Cave in the north-east of Italy and Mandrin Cave in the Middle Rhône valley have recently produced two golden eagle pedal phalanges from contexts not younger than 49.1–48.0 ky cal BP at Rio Secco and dated around 50.0 ky cal BP at Mandrin. The bones show cut-marks located on the proximal end ascribable to the cutting of the tendons and the incision of the cortical organic tissues. Also supported by an experimental removal of large raptor claws, our reconstruction explains that the deliberate detachment occurred without damaging the claw, in a way comparable at a general level with other Mousterian contexts across Europe. After excluding that these specimens met the nutritional requirements for human subsistence, we discuss the possible implications these findings perform in our current knowledge of the European Middle Palaeolithic context.


A new tarkadectine primate from the Eocene of Inner Mongolia, China: phylogenetic and biogeographic implications

Abstract: Tarka and Tarkadectes are Middle Eocene mammals known only from the Rocky Mountains region of North America. Previous work has suggested that they are members of the Plagiomenidae, an extinct family often included in the order Dermoptera. Here we describe a new primate, Tarkops mckennai gen. et sp. nov., from the early Middle Eocene Irdinmanha Formation of Inner Mongolia, China. The new taxon is particularly similar to Tarka and Tarkadectes, but it also displays many features observed in omomyids. A phylogenetic analysis based on a data matrix including 59 taxa and 444 dental characters suggests that Tarkops, Tarka and Tarkadectes form a monophyletic group—the Tarkadectinae—that is nested within the omomyid clade. Within Omomyidae, tarkadectines appear to be closely related to Macrotarsius. Dermoptera, including extant and extinct flying lemurs and plagiomenids, is recognized as a clade nesting within the polyphyletic group of plesiadapiforms, therefore supporting the previous suggestion that the relationship between dermopterans and primates is as close as that between plesiadapiforms and primates. The distribution of tarkadectine primates on both sides of the Pacific Ocean basin suggests that palaeoenvironmental conditions appropriate to sustain primates occurred across a vast expanse of Asia and North America during the Middle Eocene.


A parapithecid stem anthropoid of African origin in the Paleogene of South America

Abstract: A South American anthropoid Although there are many primate lineages in the Old World, it is thought that the New World is home to just one group, the platyrrhine monkeys, which appear to have colonized the region during the Eocene. Seiffert et al. describe a new primate species on the basis of fossil molars found in the Peruvian Amazon that appears to belong to the Parapithecidae, a group of stem anthropoid primates best known from northern Africa (see the Perspective by Godinot). The fossils appear to be from a well-differentiated lineage, suggesting that this species had been evolving within South America for some time. It is likely that the ancestors of this new species arrived via a transatlantic rafting event when sea levels dropped at the Eocene–Oligocene transition ∼32 to 35 million years ago. Science, this issue p. 194; see also p. 136 Fossils of molars suggest the existence of a South American stem anthropoid primate. Phylogenetic evidence suggests that platyrrhine (or New World) monkeys and caviomorph rodents of the Western Hemisphere derive from source groups from the Eocene of Afro-Arabia, a landmass that was ~1500 to 2000 kilometers east of South America during the late Paleogene. Here, we report evidence for a third mammalian lineage of African origin in the Paleogene of South America—a newly discovered genus and species of parapithecid anthropoid primate from Santa Rosa in Amazonian Perú. Bayesian clock–based phylogenetic analysis nests this genus (Ucayalipithecus) deep within the otherwise Afro-Arabian clade Parapithecoidea and indicates that transatlantic rafting of the lineage leading to Ucayalipithecus likely took place between ~35 and ~32 million years ago, a dispersal window that includes the major worldwide drop in sea level that occurred near the Eocene-Oligocene boundary.

african origin
paleogene
south america
eocene
afro-arabia


A Review of Shamosuchus and Paralligator (Crocodyliformes, Neosuchia) from the Cretaceous of Asia

Abstract: The crocodyliform Shamosuchus is known from numerous Late Cretaceous localities in southern and eastern Mongolia and fragmentary remains from Uzbekistan. Seven species of Shamosuchus have been named from six localities in Mongolia and three in Uzbekistan. Six species originally described as Paralligator were later referred to Shamosuchus. Only the type species, Shamosuchus djadochtaensis has been examined in detail. Many of the named species of Shamosuchus show striking similarity in size and cranial morphology but most are based on partial remains suggesting that the true species diversity is overestimated. A review of all species referred to Shamosuchus recognizes three valid taxa: Shamosuchus djadochtaensis, S. gradilifrons, and S. major. Shamosuchus sungaricus, S. borealis, and S. karakalpakensis are nomena dubia, whereas S. ancestralis, S. ulgicus, S. tersus, and S. ulanicus are junior subjective synonyms of S. gradilifrons. Phylogenetic analysis of 318 phenotypic characters recovers a Paralligatoridae clade consisting of Shamosuchus, Rugosuchus, Batrachomimus, Glen Rose Form, and Wannchampsus. Shamosuchus is non-monophyletic: S. djadochtaensis is near the base of Paralligatoridae whereas S. gradilifrons + S. major are the most deeply nested. The name Paralligator is resurrected for this clade. Rugosuchus and Batrachomimus are sister taxa to Paralligator. Paralligatoridae is closely related to Theriosuchus, hylaeochampsids and a speciose Allodaposuchus clade, which together are the sister group of Borealosuchus plus Crocodylia. These results support the presence of a diverse clade in eastern Asia and western North America throughout the Cretaceous with origins in the Late Jurassic.

shamosuchus paralligator cretaceous jurassic


Periostracum and fibrous shell microstructure in the unusual Cambrian hyolith Cupitheca

Abstract: Cupitheca is an enigmatic tubular fossil common in early Cambrian deposits worldwide. It has recently been argued to be a hyolith, probably orthothecid. Cupitheca had a dense network of mantle-filled tubules that connected to what we interpret as a continuous organic periostracum. The innermost shell layer consists of horizontal or slightly inclined bundles of fibres elongated along the a-axis and offset from other bundles at aragonitic twin angles, confirming aragonite as the original mineralogy for the shell of Cupitheca. This is a similar Shell microstructure to that inferred for Cambrian hyoliths, strengthening the claim that Cupitheca is a hyolith. This shell microstructure of bundled aragonite fibres and the tubule systems can also be seen in many Cambrian molluscs and other lophotrochozoans. In some lineages this shell texture evolved into fracture-resistant crossed lamellar microstructure and in others nacre. These transitions began to occur sometime between the mid-Cambrian and Ordovician, and nacre and crossed lamellar microstructure were the most common constituents of the inner shell layer of molluscs by the middle or late Palaeozoic Era.

shell microstructure
cupitheca
tubule
periostracum


The overlooked human influence in historic and prehistoric floods in the European Alps

Abstract: Understanding the role of climate and humans in generating mountain slope instability is crucial because such instability influences downstream fluvial activity and is a major threat to societies. Here, we use the sedimentary archive of Lake Allos (southeastern France), a mountain lake in the European Alps, to characterize mountain flood deposits and vegetation dynamics over the past 7000 yr. Our results support the interpretation of a critical threshold in catchment sensitivity to erosion at 1700 calibrated (cal.) yr B.P. (A.D. 250) probably resulting from long-term, uninterrupted impacts of human activity. The frequency and severity of floods increased dramatically after this date. These results demonstrate that underestimation of human impacts over the Holocene may pose a challenge to a clear understanding of past climate changes because paleoflood records are highly likely to have been affected by geomorphic thresholds. Natural reforestation since the end of the 19th century does not appear to be sufficient to induce a flood regime comparable to that which occurred prior to 1700 cal. yr B.P. This poses the question as to whether forest restoration in high-altitude environments is liable to foster a return to a low-erosion regime over the next decades, or whether the overall severity of soil degradation has been such as to preclude a return to previous conditions.


Cone-Beam Computed Tomography vs. Multi-Slice Computed Tomography in paleoimaging: where we stand.

Abstract: Paleopathology and anthropology are fields of research which have benefited from the use of diagnostic imaging since its introduction in the clinical setting. The deriving discipline, that is, paleoimaging, has effectively employed several diagnostic techniques. However, while Multi-Slice Computed Tomography (MSCT) has found its role in paleoimaging, Cone-Beam Computed Tomography (CBCT), despite its several advantages with regard to MSCT, is still struggling to find a clear position in this field. The aim of our study is to evaluate the possible advantages CBCT could bring to paleoimaging. We describe the characteristics and role of CBCT in clinical applications, in forensic and legal medicine, and in paleopathology. We report the study of an ancient mandible by means of CBCT and MSCT, in order to compare the quality of the images in terms of spatial resolution. CBCT allows to obtain good quality images of mineralized tissues. Moreover, the possibility of imaging metallic manufacts makes the technique suitable for the study not only of bony remains, but also of museum and archaeological artifacts. Our study highlights the strengths of CBCT as a valid imaging technique for the study of ancient bone remains and manufacts. A revision of the current uses of CBCT is provided and gives insights into the possible role it can cover in bioarchaeological studies. Further evaluation is needed in terms of possible applications of this technique to paleopathology. We strongly encourage the use of CBCT in paleoimaging, and suggest a broader application of the technique to the study of archaeological samples.

paleopathology
medicine
cone-beam computed tomography


Area-cladograms of Circum-Mediterranean taxa in relation to Mediterranean palaeogeography

Abstract: Biogeographic characteristics of nine taxon- area-cladograms of various Circum-Mediterranean terres- trial animal groups are compared. Correlation with palaeo- geographic reconstructions suggests Oligocene and especially Miocene diversification within these groups. The oldest faunal elements are found in the western part of the region which dates from well before the Miocene. Origin of younger lineages is considered linked with the Late Oligocene-Early Miocene formation of a landmass which separated Tethys and Paratethys. Major divergence is hypothesized to have been achieved by subsequent vicariant and distributional events throughout the Mediter- ranean during the Miocene. The palaeo-biogeographic cor- relation results in estimates of the ages of lineages for the newt genus Triturus which largely correspond to the esti- mates obtained from various biochemical and molecular studies.

tethys
paratethys
several circum-mediterranean faunae
neogene palaeogeography
entomofauna


Dinosaurian Soft Tissues Interpreted as Bacterial Biofilms

Abstract: A scanning electron microscope survey was initiated to determine if the previously reported findings of “dinosaurian soft tissues” could be identified in situ within the bones. The results obtained allowed a reinterpretation of the formation and preservation of several types of these “tissues” and their content. Mineralized and non-mineralized coatings were found extensively in the porous trabecular bone of a variety of dinosaur and mammal species across time. They represent bacterial biofilms common throughout nature. Biofilms form endocasts and once dissolved out of the bone, mimic real blood vessels and osteocytes. Bridged trails observed in biofilms indicate that a previously viscous film was populated with swimming bacteria. Carbon dating of the film points to its relatively modern origin. A comparison of infrared spectra of modern biofilms with modern collagen and fossil bone coatings suggests that modern biofilms share a closer molecular make-up than modern collagen to the coatings from fossil bones. Blood cell size iron-oxygen spheres found in the vessels were identified as an oxidized form of formerly pyritic framboids. Our observations appeal to a more conservative explanation for the structures found preserved in fossil bone.

bacterial biofilm
blood vessel
fossil bone


Discovery of the oldest Gobius (Teleostei, Gobiiformes) from a marine ecosystem of Early Miocene age

Abstract: Gobiidae (Gobiiformes, Teleostei) is among the largest families of vertebrates. These fishes are distributed worldwide and contribute significantly to species diversity in marine habitats and reefs. However, their fossil record is sparse prior to the Miocene and little is known about the course of diversification of the clade. Here we report exceptionally well-preserved skeletal remains of the oldest known Gobius from an Early Miocene (Burdigalian) marine ecosystem of Central Europe (Czech Republic). Gobius jarosi Přikryl & Reichenbacher sp. nov. is dated to 19.1–20.4 Ma by biostratigraphical analysis of calcareous nannoplankton from small fragments of the holotype matrix. Gobius jarosi sp. nov. is characterized by a pterygiophore formula of 3-22110 and a premaxilla with a distinctive postmaxillary process, has 11 abdominal and 16–17 caudal vertebrae, six thin spines in the first dorsal fin and one spine and 12 soft rays in the second dorsal fin, one spine and 11 rays in the anal fin, and two anal fin pterygiophores preceding the first haemal spine. Large ctenoid scales cover the body except for its anterior portion and the head. A comparative analysis of meristic and osteological data suggests close affinities between G. jarosi sp. nov. and the extant species G. niger, G. roulei and G. vittatus. Accompanying fish fossils and nannoplankton assemblages indicate that G. jarosi sp. nov., like G. roulei and G. vittatus, lived in an inshore to offshore marine ecosystem. The discovery of such an early member of the lineage leading to the present-day species of Gobius has important implications for the origin and evolution of the Gobiidae, and indicates that diversification of the European Gobiidae began in, but not before, the Early Miocene. http://zoobank.org/urn:lsid:zoobank.org:pub:3229739B-3428-4DFB-9588-4CE875D732D8

gobiiformes
marine ecosystem
diversification
gobioid


Silurian retiolitid graptolites: Morphology and evolution

Abstract: Developmental mode and proximal structures are commonly accepted as the best for the recognition of high-level taxonomic categories within the Graptoloidea. The petalolithids and retiolitids are unique in possessing a virgellar ancora and in the latter, distal ancora development. The ancora structures are considered homologous, and the ancorate petalolithids are considered to be the direct ancestors to the retiolitids. The Retiolitidae are unique among the diplograptoids in possessing (1) outer, lateral, ancora sleeve walls (derived from distal extension of the ancora), and (2) a skeletal framework of bandaged lists between which are a succession of very thin and rarely preserved fusellar layers. Retiolitids possess different kinds of thecal profiles and two types of micro-ornamentation on the lists, and these have served to distinguish between the subfamilies Retiolitinae and Plectograptinae. Complete retiolitid morphological terminology is clarified and explained. Cladistic analysis of the retiolitids provides some measure of a better understanding of retiolitid evolution, but adds only modest support for the retention of the two subfamily categories.

ancora
list
holoretiolites
rotaretiolites
early taxa


Family level classification within Thylacocephala, with comments on their evolution and possible relationships

Abstract: Thylacocephala are among the most problematic of arthropod fossils. Various authors have allied them with all manner of crustacean groups, including branchiopods, cirripedes, remipedes, and malacostracans. They have a very apomorphic body plan often marked by hypertrophy of the compound eyes, three pairs of large raptorial subchelate limbs, eight sets of well-developed phyllobranch gills, and from 8 to at least 16 posterior trunk somites bearing paddle-like limbs. They have been thought of as a distinct class composed of two orders, Concavicarida and Conchyliocarida, but membership within the orders varies according to authors, and no familial divisions have been proposed within the orders until now. This lack of taxonomic structure inhibits organization of available information concerning the paleoecology, paleogeography, and phylogenetic relationships of thylacocephalans. A working hypothesis for the higher taxonomy within the class is proposed here. This entails a redefinition of the two orders, and recognition of seven families, five of them new: Austriocarididae Glaessner, 1931, Clausocarididae Arduini, 1992 (new status), Concavicarididae n. fam., Dollocarididae, n. fam., Microcarididae n. fam., Ostenocarididae n. fam. and Protozoeidae n. fam.


Abstract: Domning, Daryl P., Clayton E. Ray, and Malcolm C. McKenna. Two New Oligocene Desmostylians and a Discussion of Tethytherian Systematics. Smithsonian Contributions to Paleobiology, number 59, 56 pages, 23 figures, 1986.— A new genus, comprising two new species of desmostylians, is described from marine Oligocene deposits of the Pacific Northwest. Behemotops proteus, new genus, new species, is based on an immature mandibular ramus and apparently associated skeletal fragments from the middle or (more likely) upper Oligocene lower part of the Pysht Formation of Clallam County, Washington. A related new species, Behemotops emlongi, is founded on a mandibular ramus of an old individual and a mandibular fragment with canine tusk from the uppermost Oligocene (early Arikareean equivalent) Yaquina Formation of Lincoln County, Oregon. The two new species are the most primitive known desmostylians and compare favorably with the primitive Eocene proboscideans Anthracobune and Moeritherium, and to the still more primitive tethythere Minchenella from the Paleocene of China. For many years the Desmostylia were widely regarded as members of the mammalian order Sirenia before being accepted as a taxon coordinate with the Sirenia and Proboscidea (Reinhart, 1953). On the basis of cladistic analysis we go a step further and regard the Desmostylia as more closely related to Proboscidea than to Sirenia because the Desmostylia and Proboscidea are interpreted herein to share a more recent common ancestor than either order does with the Sirenia. This analysis also suggests that the common ancestor of the Proboscidea and Desmostylia (but not the Sirenia) had suppressed P5 and the original last molar. These characters may be convergent with some other mammals. The Superorder Tokotheria McKenna, 1975, was originally thought to be characterized by loss of both P5 and M3. However, because early sirenians do not show these losses, they may have occurred independently in the common ancestor of proboscideans and desmostylians and in various other tokotheres. The late Paleocene genus Minchenella Zhang, 1980, from China, is a suitable candidate to be the common ancestor of both the Desmostylia and the Proboscidea. It possesses a small entoconid II on M:<. The Eocene genus Lammidhania Gingerich, 1977, from Pakistan, and the late Paleocene and/ or early Eocene Chinese and Mongolian phenacolophids had not acquired an entoconid II on M^ but are otherwise similar to Minchenella and the anthracobunids. The Asiatic occurrence of phenacolophids, Lammidhania, Minchenella, and anthracobunids suggests an Asian origin for the Proboscidea and is in accord with the exclusively Pacific distribution of the Desmostylia. We believe that desmostylians were amphibious herbivores that fed on marine algae and angiosperms, and that at least the earlier taxa depended to a large extent on plants exposed in the intertidal zone. OFFICIAL PUBLICATION DATE i.s handstamped in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SERIES COVER DESIGN: The trilobite Phacops rana Green. Library of Congress Cataloging in Publication Data Domning, Daryl P. Two new Oligocene desmostylians and a discussion of tethytherian systematics. (Smithsonian contributions to paleobiology ; no. 59) Bibliography: p. Supt. of Docs, no.: SI 1.30:59 1. Behemotops proteus. 2. Beheniotopsemlongi. 3. Desmostylia. 4. Proboscidea, Fossil. 5. Paleontology—Oligocene. 6. Paleontology—Washington(State)—Clallam County. 7. Paleontology—Oregon—Lincoln County. 1. Ray, Clayton Edward. II. McKenna Malcolm C. 111. Title. IV. Series. QE701.S56no. 59 [QE882.D45J 560 s [569'.6] 85-600322

new oligocene desmostylian
tethytherian systematic
desmostylia
other mammal


The latitudinal diversity gradient of tetrapods across the Permo-Triassic mass extinction and recovery interval

Abstract: The decline in species richness from the equator to the poles is referred to as the latitudinal diversity gradient (LDG). Higher equatorial diversity has been recognized for over 200 years, but the consistency of this pattern in deep time remains uncertain. Examination of spatial biodiversity patterns in the past across different global climate regimes and continental configurations can reveal how LDGs have varied over Earth history and potentially differentiate between suggested causal mechanisms. The Late Permian–Middle Triassic represents an ideal time interval for study, because it is characterized by large-scale volcanic episodes, extreme greenhouse temperatures and the most severe mass extinction event in Earth history. We examined terrestrial and marine tetrapod spatial biodiversity patterns using a database of global tetrapod occurrences. Terrestrial tetrapods exhibit a bimodal richness distribution throughout the Late Permian–Middle Triassic, with peaks in the northern low latitudes and southern mid-latitudes around 20–40° N and 60° S, respectively. Marine reptile fossils are known almost exclusively from the Northern Hemisphere in the Early and Middle Triassic, with highest diversity around 20° N. Reconstructed terrestrial LDGs contrast strongly with the generally unimodal gradients of today, potentially reflecting high global temperatures and prevailing Pangaean super-monsoonal climate system during the Permo-Triassic.

latitudinal diversity gradient
tetrapod
equator
low latitude


First trace and body fossil evidence of a burrowing, denning dinosaur

Abstract: A fossil discovery in the mid-Cretaceous Blackleaf Formation of southwest Montana, USA, has yielded the first trace and body fossil evidence of burrowing behaviour in a dinosaur. Skeletal remains of an adult and two juveniles of Oryctodromeus cubicularis gen. et sp. nov., a new species of hypsilophodont-grade dinosaur, were found in the expanded distal chamber of a sediment-filled burrow. Correspondence between burrow and adult dimensions supports Oryctodromeus as the burrow maker. Additionally, Oryctodromeus exhibits features of the snout, shoulder girdle and pelvis consistent with digging habits while retaining cursorial hindlimb proportions. Association of adult and young within a terminal chamber provides definitive evidence of extensive parental care in the Dinosauria. As with modern vertebrate cursors that dig, burrowing in Oryctodromeus may have been an important adaptation for the rearing of young. Burrowing also represents a mechanism by which small dinosaurs may have exploited the extreme environments of polar latitudes, deserts and high mountain areas. The ability among dinosaurs to find or make shelter may contradict some scenarios of the Cretaceous–Paleogene impact event. Burrowing habits expand the known range of nonavian dinosaur behaviours and suggest that the cursorial ancestry of dinosaurs did not fully preclude the evolution of different functional regimes, such as fossoriality.

body fossil evidence
burrowing
usa
behaviour
first trace


Timing of Early Cretaceous angiosperm diversification and possible links to major paleoenvironmental change

Abstract: Palynological records from the Western Portuguese and Algarve basins (Portugal) provide new insights on the timing and pattern of the early diversification of angiosperms (flowering plants) and its relationship to global environmental perturbations during the late Early Cretaceous. Angiosperm pollen displays a stepwise increase in both diversity and relative abundance during the late Barremian to middle Albian interval (ca. 124–104 Ma), reflecting the incipient radiation of flowering plants in lower midlatitude floras. Our results provide new evidence for the age interpretation of the previously described angiosperm mesofossil floras and associated in situ pollen assemblages from the Western Portuguese basin, until now interpreted as Barremian or possibly Aptian in age. Biostratigraphic and sedimentologic evidence indicates a post-Aptian age for these assemblages, hence demonstrating a major radiation phase of angiosperms during the early Albian. Correlation of the angiosperm pollen record with data on global paleoenvironmental changes suggests a link between the rapid adaptive radiation of flowering plants and major climatic and oceanographic perturbations during the late Early Cretaceous.

diversification
link
paleoenvironmental change


New Varanid Remains from the Miocene (MN4–MN5) of France: Inferring Fossil Lizard Phylogeny from Subsets of Large Morphological Data Sets

Abstract:
ABSTRACT
 Fossil vertebrae from the early Miocene of France (Loire Basin) are described. They show several characters generally regarded as varanid synapomorphies. A phylogenetic analysis of these vertebrae is performed with a subset of morphological data taken from several large morphological data sets (vertebral characters) and it confirms an attribution to varanid lizards. Moreover, referral of isolated vertebrae from the Eocene-Oligocene of Egypt to varanids is confirmed. The use of subsets of large morphological data sets in phylogenetic analysis of fossils (especially incomplete remains) is discussed and advocated for, and we argue that convergence between tree topologies obtained from different kinds of data sets is a key issue in inferring the phylogenetic position of fossil taxa.

miocene
france
vertebral character
fossil taxa


Fins into Limbs - Edited by B. K. Hall

Abstract:
For those of us whose careers in developmental biology stretch back a long way, the most exciting insights in the last forty years have, without doubt, been in the area of evolutional developmental biology, or evo-devo. The story has a history. Erasmus Darwin and others at the end of the 18th century advanced the possibility of evolution and in 1859, Charles Darwin published the core mechanism in The Origin of Species. He was, however, very thin on the relationship between evolution and embryology and was not always right, for example: ‘From what we know of the embryos of mammals, birds, fishes and vertebrates, these animals are the modified descendents of some ancient progenitor, which was furnished in its adult state with branchiae, a swim-bladder, four fish-like limbs, and a long tail, all fitted for aquatic life’. Haeckel, the major comparative anatomist at the end of the 19th century, got it wrong with his biogenetic law, which essentially states that evolution adds to, rather than modifies, embryonic development.

It seems to have been Waddington, harking back to von Baer, who was the first person to emphasize that the roots of anatomical variation lay in mutations that affected development. At a more practical level, a great deal of anatomical and palaeontological data on the relationships between development and evolution has been collected during the last two centuries. It was not until the early 1980s, however, with the rise of eukaryotic molecular genetics and the recognition that hox patterning underpinned so much of axial organization across the Bilateria, that the field could start to put molecular flesh on the bare bones of the earlier theoretical and anatomical insights.

From these beginnings, the results of a lot of hard work over the last 25 years linking molecular biology, palaeontology, bioinformatics, evolutional homologies and experimental embryology have been that we now understand something of the molecular details of the development and evolution of biological structure. Nowhere, however, have the successes been as great as in the evolution of fins into limbs, a homology that first seems to have been pointed out by Carl Gegenbaur in 1865 and most recently analysed in Jenny Clack's monograph Gaining Ground.

The publication of the multi-authored Fins into Limbs carries on where Gaining Ground ended: its three sections and 19 chapters explore almost every aspect of limb evolution and development. The first section discusses evolutional history, skeletal changes in the fin-to-limb transition (obviously written before the publication of Tiktaalik roseae), locomotion and evolutional novelties. The eight chapters on development (the only section with molecular data) cover everything in the area from patterning mechanisms to postnatal growth to regeneration. The last section on transformation has seven chapters that review the evolution of the amphibian and mammalian appendicular skeletons, sesamoids and ossicles, limb diversity, and adaptations for flying, digging and swimming.

Let me not beat about the bush: I think Fins into Limbs is the best and most enjoyable multi-author book that I have come across in years. It will be a standard in the field for some time and anyone with the slightest interest in evo-devo, as well as anyone with even a passing interest in fins and/or limbs, should read it. Why am I so enthusiastic? There are several reasons and the first is the general high scientific quality of the chapters, several of which contain important reference material. The second is the way that the chapters cohere to give such a rich picture of a fascinating area, building on their historical roots where appropriate while being, so far as I can see, pretty well up to date. The third is the way that knowledge in so many areas of science is brought together to illuminate one or another aspect of the story – it is a very modern book. For all this, much credit goes of course to the editor, but to use the quote from William Harvey that Joseph Needham cites in the dedication of his wonderful book A History of Embryology, ‘all did well’. Actually there is a different sort of reason for being so uncritical: if something is enjoyable to read, it disarms the critical instincts of the reader, and I felt disarmed!

Many of the chapters are of general interest (evolution, development), although this may just mean that I had the appropriate background to read them without the need to run to my reference books and wikis. Some seemed to me to be more specialized (almost anything to do with the anatomical details of adaptation was new to me) but I enjoyed finding out about some wonderful obscurities: there are, for example, more than 20 sesamoids and inconstant ossicles in the human foot, the first time-lapse study of aquatic motion was first carried out by Marey in 1890 on a tethered skate (the pictures were good!), and there are four types and three grades of joints – a challenge to those who investigate molecular pathways and systems.

Given that so much is good in this book, it may seem ungenerous for a reviewer to think about the next edition and what it will contain, but, with the intention of encouraging it, I will. It is hard to think that there is much more to be said on the anatomical side but I did come away with the feeling that our knowledge of the molecular underpinnings of limb development is still rudimentary. On the basis of expression and transgenic studies, we know the roles of many genes involved in limb development and understand the basics of the networks in which they participate, but there is a large gap between our knowledge of the regulatory pathways and the anatomical structures that they generate. Similarly, we have little insight into how mutation leads to the quantitative changes in pathway kinetics that, in turn, lead to the wide range of limb forms among vertebrates. It is not unreasonable to expect, in the near future, a great deal of research into the dynamics of the molecular events downstream of transcriptional activation and in pathway kinetics.

It is only in this area of computational biology that Fins into Limbs is thin. Network dynamics is one aspect where we can expect progress; modelling of mutation rates to changes in phenotype will be another and the linking of anatomical change to functional change will be a third. The considerable progress currently being made in the quantitative modelling of musculo-skeletal anatomy to predict running and jumping activity is allowing us to link changes in limb anatomy to changes in behaviour, and this in turn will increase our knowledge of how extinct animals lived and evolved. We can look forward to real progress being made in this area of biomechanics in the next few years, and incorporated into the next edition of Fins into Limbs– for now, it is enough to enjoy a very good and important book.

limbs
field
appendicular skeleton
biomechanic
fin


The RNA world and the origin of metabolic enzymes

Abstract: An RNA world has been placed centre stage for explaining the origin of life. Indeed, RNA is the most plausible molecule able to form both a (self)-replicator and to inherit information, necessities for initiating genetics. However, in parallel with self-replication, the proto-organism had to obtain the ability to catalyse supply of its chemical constituents, including the ribonucleotide metabolites required to replicate RNA. Although the possibility of an RNA-catalysed metabolic network has been considered, it is to be questioned whether RNA molecules, at least on their own, possess the required catalytic capacities. An alternative scenario for the origin of metabolism involves chemical reactions that are based on environmental catalysts. Recently, we described a non-enzymatic glycolysis and pentose phosphate pathway-like reactions catalysed by metal ions [mainly Fe(II)] and phosphate, simple inorganic molecules abundantly found in Archaean sediments. While the RNA world can serve to explain the origin of genetics, the origin of the metabolic network might thus date back to constraints of environmental chemistry. Interestingly, considering a metal-catalysed origin of metabolism gives rise to an attractive hypothesis about how the first enzymes could have formed: simple RNA or (poly)peptide molecules could have bound the metal ions, and thus increased their solubility, concentration and accessibility. In a second step, this would have allowed substrate specificity to evolve.


Grotta del Cavallo (Apulia-Southern Italy). The Uluzzian in the mirror.

Abstract: The Uluzzian techno-complex is commonly considered to be a "transitional industry" mostly on the basis of some inferred characteristics such as a chiefly flake-based production, a small amount of Upper Palaeolithic-like tools and a combination of Middle and Upper Palaeolithic elements both in the toolkit and in the technical systems. Following its discovery, the Uluzzian was identified as the Italian counterpart of the French Châtelperronian and attributed to Neandertals. However, a study issued in 2011 has established the modern character of the two deciduous teeth found in 1964 in the Uluzzian deposit of Grotta del Cavallo, fostering renewed interests to the Uluzzian culture, which real nature is almost unknown to the international scientific community. Here we provide preliminary results of the study on the lithic assemblage from the earliest Uluzzian layer and on backed pieces from the whole Uluzzian sequence of Grotta del Cavallo (Apulia, Italy), the type site of the Uluzzian. Moreover, besides a thorough review on the stratigraphy of Grotta del Cavallo (Supplementary Materials), we provide updated information on the human remains by presenting two unpublished teeth from the reworked deposit of the same cave. We conclude that the early Uluzzians demonstrate original technological behavior and innovations devoid of any features deriving or directly linked with the late Mousterian of Southern Italy. Therefore, the novelty nature of the Uluzzian techno-complex (with respect to the preceding Mousterian) complies with the recent reassessment of the two deciduous teeth from Grotta del Cavallo in suggesting an earliest migration of modern humans in southern Europe around 45,000 years ago.

italy
uluzzian
transitional industry
industry


Systematics and phylogeny of Vasseuromys (Mammalia, Rodentia, Gliridae) with a description of a new species from the late Miocene of eastern Europe

Abstract: Vasseuromys is a species‐rich genus of small‐ to medium‐sized glirids spanning the latest Oligocene to late Miocene of Europe and western Asia. Despite extensive discoveries over the past 50 years, little phylogenetic work has been done on Vasseuromys. This study presents the first phylogenetic analysis of the genus that includes all the described species and a new taxon Vasseuromys tectus sp. nov. from the late Miocene of eastern Europe, providing the first insights into the evolutionary relationships within the clade. Results suggest that the genus is clearly paraphyletic. Two strongly supported genus‐level clades are recognized within ‘Vasseuromys’: a restricted Vasseuromys clade (containing the three species, V. pannonicus, V. rugosus and V. tectus) and the Glirulus clade that includes ‘Vasseuromys’ duplex. The remaining ‘Vasseuromys’ species are found to constitute a set of paraphyletic taxa, with the polyphyletic ‘Ramys’ nested within it. The genus Gliruloides is synonymized with Glirulus. Vasseuromys tectus sp. nov. is the most derived member of the genus in having a greater number of cheek teeth ridges including constantly present anterotrope, centrotrope, second prototrope on M1–2, third metatrope on M2, two to three posterotropids on p4 and strong ectolophids on lower molars. The results of the study confirm a European origin for Vasseuromys while suggesting that the late Miocene species of the genus dispersed from the east in the early Turolian.

vasseuromys
late miocene
europe
phylogenetic analysis


Taxonomy of the proterosuchid archosauriforms (Diapsida: Archosauromorpha) from the earliest Triassic of South Africa, and implications for the early archosauriform radiation

Abstract: Proterosuchidae is one of the first clades of Archosauriformes (archosaurs and closely related species) to appear in the fossil record, with the richest sample of the group coming from the Lystrosaurus Assemblage Zone (earliest Triassic) of South Africa. Four nominal proterosuchid species were described from South Africa during the twentieth century (Proterosuchus fergusi, Chasmatosaurus vanhoepeni, Chasmatosaurus alexanderi and Elaphrosuchus rubidgei), but interpretations of their taxonomy have been widely disparate. The most recent taxonomic revision concluded that P. fergusi is the only valid species and that the other nominal species are junior subjective synonyms of this taxon. This proposal was based on the interpretation that anatomical differences between the nominal species could be explained as a result of ontogenetic changes and/or post‐mortem deformation. The recent discoveries of multiple new South African proterosuchid specimens provide an impetus to revisit their taxonomy. Based upon a comprehensive re‐examination of all known specimens, as well as examination of other proterosuchid taxa in collections worldwide, we conclude that the holotype of Proterosuchus fergusi is undiagnostic. As a result, we propose a neotype (RC 846) for the species. ‘Chasmatosaurus vanhoepeni’ and ‘Elaphrosuchus rubidgei’ are considered subjective junior synonyms of P. fergusi. ‘Chasmatosaurus’ alexanderi is considered a valid species, for which we propose the new combination P. alexanderi comb. nov. A third species, P. goweri sp. nov., is erected on the basis of a single specimen (NMQR 880). All three species recognized here are taxonomically distinct from a previously described archosauriform maxilla from the lower Lystrosaurus AZ. As a result, we recognize a minimum of four archosauriform species following the Permo‐Triassic mass extinction in South Africa. Our results suggest a greater species richness of earliest Triassic archosauriforms than previously appreciated, but that archosauriform morphological disparity remained low and did not expand until the late Early Triassic – early Mid‐Triassic.

proterosuchid specimen
early triassic
taxonomy


Testing the role of the Red Queen and Court Jester as drivers of the macroevolution of Apollo butterflies

Abstract: In macroevolution, the Red Queen (RQ) model posits that biodiversity dynamics depend mainly on species-intrinsic biotic factors such as interactions among species or life-history traits, while the Court Jester (CJ) model states that extrinsic environmental abiotic factors have a stronger role. Until recently, a lack of relevant methodological approaches has prevented the unraveling of contributions from these two types of factors to the evolutionary history of a lineage. Here we take advantage of the rapid development of new macroevolution models that tie diversification rates to changes in paleoenvironmental (extrinsic) and/or biotic (intrinsic) factors. We inferred a robust and fully-sampled species-level phylogeny, as well as divergence times and ancestral geographic ranges, and related these to the radiation of Apollo butterflies (Parnassiinae) using both extant (molecular) and extinct (fossil/morphological) evidence. We tested whether their diversification dynamics are better explained by a RQ or CJ hypothesis, by assessing whether speciation and extinction were mediated by diversity-dependence (niche filling) and clade-dependent host-plant association (RQ) or by large-scale continuous changes in extrinsic factors such as climate or geology (CJ). For the RQ hypothesis, we found significant differences in speciation rates associated with different host-plants but detected no sign of diversity-dependence. For CJ, the role of Himalayan-Tibetan building was substantial for biogeography but not a driver of high speciation, while positive dependence between warm climate and speciation/extinction was supported by continuously varying maximum-likelihood models. We find that rather than a single factor, the joint effect of multiple factors (biogeography, species traits, environmental drivers, and mass extinction) is responsible for current diversity patterns, and that the same factor might act differently across clades, emphasizing the notion of opportunity. This study confirms the importance of the confluence of several factors rather than single explanations in modeling diversification within lineages.

red queen
court jester
macroevolution
abiotic factor
diversification


Long-term legacy of massive carbon input to the Earth system: Anthropocene versus Eocene

Abstract: Over the next few centuries, with unabated emissions of anthropogenic carbon dioxide (CO2), a total of 5000 Pg C may enter the atmosphere, causing CO2 concentrations to rise to approximately 2000 ppmv, global temperature to warm by more than 8°C and surface ocean pH to decline by approximately 0.7 units. A carbon release of this magnitude is unprecedented during the past 56 million years—and the outcome accordingly difficult to predict. In this regard, the geological record may provide foresight to how the Earth system will respond in the future. Here, we discuss the long-term legacy of massive carbon release into the Earth's surface reservoirs, comparing the Anthropocene with a past analogue, the Palaeocene–Eocene Thermal Maximum (PETM, approx. 56 Ma). We examine the natural processes and time scales of CO2 neutralization that determine the atmospheric lifetime of CO2 in response to carbon release. We compare the duration of carbon release during the Anthropocene versus PETM and the ensuing effects on ocean acidification and marine calcifying organisms. We also discuss the conundrum that the observed duration of the PETM appears to be much longer than predicted by models that use first-order assumptions. Finally, we comment on past and future mass extinctions and recovery times of biotic diversity.

earth system
anthropocene
carbon release
petm
long-term legacy


Traits and evolution of wing venation pattern in paraneopteran insects

Abstract: Two different patterns of wing venation are currently supposed to be present in each of the three orders of Paraneoptera. This is unlikely compared with the situation in other insects where only one pattern exists per order. We propose for all Paraneoptera a new and unique interpretation of wing venation pattern, assuming that the convex cubitus anterior gets fused with the common stem of median and radial veins at or very near to wing base, after separation from concave cubitus posterior, and re‐emerges more distally from R + M stem. Thereafter, the vein between concave cubitus posterior and CuA is a specialized crossvein called “cua‐cup,” proximally concave and distally convex. We show that despite some variations, that is, cua‐cup can vary from absent to hypertrophic; CuA can re‐emerge together with M or not, or even completely disappear, this new interpretation explains all situations among all fossil and recent paraneopteran lineages. We propose that the characters “CuA fused in a common stem with R and M”and “presence of specialized crossvein cua‐cup” are venation apomorphies that support the monophyly of the Paraneoptera. In the light of these characters, we reinterpret several Palaeozoic and early Mesozoic fossils that were ascribed to Paraneoptera, and confirm the attribution of several to this superorder as well as possible attribution of Zygopsocidae (Zygopsocus permianus Tillyard, 1935) as oldest Psocodea. We discuss the situation in extinct Hypoperlida and Miomoptera, suggesting that both orders could well be polyphyletic, with taxa related to Archaeorthoptera, Paraneoptera, or even Holometabola. The Carboniferous Protoprosbolidae is resurrected and retransferred into the Paraneoptera. The genus Lithoscytina is restored. The miomopteran Eodelopterum priscum Schmidt, 1962 is newly revised and considered as a fern pinnule. In addition, the new paraneopteran Bruayaphis oudardi gen. nov. et sp. nov. is described fromthe Upper Carboniferous of France (see Supporting Information). J. Morphol., 2012. © 2011 Wiley Periodicals, Inc.


Likelihood reinstates Archaeopteryx as a primitive bird

Abstract: The widespread view that Archaeopteryx was a primitive (basal) bird has been recently challenged by a comprehensive phylogenetic analysis that placed Archaeopteryx with deinonychosaurian theropods. The new phylogeny suggested that typical bird flight (powered by the front limbs only) either evolved at least twice, or was lost/modified in some deinonychosaurs. However, this parsimony-based result was acknowledged to be weakly supported. Maximum-likelihood and related Bayesian methods applied to the same dataset yield a different and more orthodox result: Archaeopteryx is restored as a basal bird with bootstrap frequency of 73 per cent and posterior probability of 1. These results are consistent with a single origin of typical (forelimb-powered) bird flight. The Archaeopteryx–deinonychosaur clade retrieved by parsimony is supported by more characters (which are on average more homoplasious), whereas the Archaeopteryx–bird clade retrieved by likelihood-based methods is supported by fewer characters (but on average less homoplasious). Both positions for Archaeopteryx remain plausible, highlighting the hazy boundary between birds and advanced theropods. These results also suggest that likelihood-based methods (in addition to parsimony) can be useful in morphological phylogenetics.

archaeopteryx
phylogenetic analysis
probability