bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Three‐Dimensionally Preserved Xiphosuran Chelicerate from the Montceau‐Les‐Mines Lagerstätte (Carboniferous, France)
Authors: Racheboeuf Patrick R. , Vannier Jean , Anderson Lyall I.
Published: November 2003

Excellent three dimensional preservation of 142 specimens of Alanops magnificus gen. et sp. nov. (Chelicerata: Xiphosura) from the Stephanian Konservat‐Lagerstätte of Montceau‐les‐Mines (Saône‐et‐Loire, France), exposes the carapace design and hitherto unrecorded details of fossil xiphosuran ventral anatomy, and makes possible an interpretation of appendicular functional morphology. All legs are long, slender and chelate. The chelate condition of the fifth leg and the shape of the prosoma (highly vaulted with a subvertical frontal area) indicate that the animal was neither a burrower like Recent xiphosurans (e.g. Limulus) nor an active swimmer as suggested for other extinct forms, but was more likely to have been a benthic crawler. The ability to fold up is attested by both partly enrolled specimens showing appendages withdrawn into the prosomal cavity, and by coaptive devices on the external and internal margins of both prosoma and opisthosoma. The low‐level articulation system at the boundary between the two shields allowed both the carapace closure and the complete outstretching of the animal. The unusually small adult size of Alanops magnificus gen. et sp. nov. combined with the loss of ophthalmic ridges and spines is interpreted as indicating a paedomorphic derivation from a bellinurine stock. The depositional environment (limnic intramontane basin) and faunal association (dominated by syncarids and bivalves) of Alanops indicate that the animal probably lived in fresh water.
The Ordovician Trilobite Carolinites, A Test Case for Microevolution in A Macrofossil Lineage
Authors: McCormick Tim , Fortey Richard A.
Published: November 2003

We use geometric morphometrics to test a claim that the Ordovician trilobite Carolinites exhibits gradualistic evolution. We follow a previously proposed definition of gradualism, and define the criteria an ideal microevolutionary case study should satisfy. We consider the Lower–Middle Ordovician succession at Ibex, western Utah to meet these criteria. We discovered examples of: (1) morphometric characters which fluctuate with little or no net change; (2) characters which show abrupt ‘step’ change; (3) characters which show transitional change through intermediate states. Examples belonging to (2) and (3) exhibit reversals. The transitional characters were tested against a null hypothesis of symmetrical random walk. The tests indicated that they were not changing under sustained directional selection. Two alternative interpretations are possible. (1) The characters are responding to random causes (genetic drift or rapidly fluctuating selection pressures) or to causes that interact in so complex a way that they appear random. This observation may be applicable to most claimed cases of gradualistic evolution in the literature. (2) Sampling was at too poor a resolution to allow meaningful testing against the random walk. If so, then this situation is likely to apply in most evolutionary case studies involving Palaeozoic macrofossils.
Sharks, Rays and A Chimaeroid from the Kimmeridgian (Late Jurassic) of Ringstead, Southern England
Authors: Underwood Charlie J.
Published: November 2003

Sampling of a lenticular concentration of vertebrate debris and associated sediments from the lower Kimmeridgian of southern England has allowed the study of a diverse and abundant assemblage of chondrichthyan remains. A number of previously undescribed species are recorded, of which three new species are named; Squatina? frequens, Synechodus plicatus and Protospinax planus. Additional diagnosis of the genus Paracestracion Koken is given to allow its identification from dental remains. Several nominal batoid species are synonymised with Spathobatis bugesiacus Thiolliere. This assemblage is considered to be typical of Middle–Late Jurassic neritic environments, and is compared to other contemporaneous selachian faunas.
Silurian (Wenlock–ludlow) Graptolites from Bolivia
Authors: Maletz Jörg , Soruco Ramiro Suárez , Egenhoff Sven O.
Published: November 2003

Well preserved middle to upper Silurian (Wenlock–Ludlow) graptolites from Bolivia are described for the first time. Generally monospecific graptolite faunas, of species largely endemic to South America, are found in a few levels in the lower part of the Kirusillas, Rio Carrasco and Uncía formations. The oldest identified level yields specimens of Pristiograptus praedeubeli (Jaeger) and is referred to the upper Wenlock. Younger faunas belong to the Ludlow and include Saetograptus, Monograptus and Neodiversograptus specimens. These may be referred to the Gorstian (lower Ludlow). The fauna includes Saetograptus argentinus robustus ssp. nov. and Monograptus bolivianus sp. nov.
A New Basal Lystrosaurid Dicynodont from the Upper Permian of South Africa
Authors: Maisch Michael W.
Published: November 2003

A new genus and species of late Permian dicynodont, Kwazulusaurus shakai, is described on the basis of a complete skull from the late Permian Dicynodon Assemblage Zone of the South African Beaufort Group. It is an advanced form which shows characters, such as the shape of the snout and the loss of the ectopterygoid, that link it to the early Triassic genus Lystrosaurus. Kwazulusaurus represents the most basal member of the lystrosaurian lineage. The phylogeny of progressive pristerodontian dicynodonts is discussed. It appears possible that the Kannemeyeriiformes and Lystrosauridae do not form a monophylum, as previously assumed. Instead a sister‐group relationship between lystrosaurids and dicynodontids plus kannemeyeriiforms is suggested.
Diversification in Polypteriformes and Special Comparison With the Lepisosteiformes
Authors: Gayet M. , Meunier F. J. , Werner C.
Published: November 2003

Polypteriformes (or Cladistia) and Lepisosteiformes (or Ginglymodi) are two groups of freshwater fishes with ganoid scales. The earliest fossil records of these taxa are Albian (Lepisosteiformes) and Cenomanian (Polypteriformes) respectively in Gondwana; they are still extant. The ‘first’ appearance of the two groups in the fossil record (explosive in polypteriforms, gradual in lepisosteiforms) as well as their evolutionary mode (diversification/disparity or replacement) is described in detail. The lepisosteiforms appear to show a rapid radiation of post‐Palaeozoic clades immediately upon origination, while the polypteriforms represent a counter‐example with their sudden diversification and their sudden acquisition of several ‘key innovations’.
A Re‐evaluation of Small Tetrapods from the Middle Triassic Otter Sandstone Formation of Devon, England
Authors: Spencer P. S. , Storrs G. W.
Published: November 2003

Material of small sauropsids from the Otter Sandstone Formation of east Devon (Sherwood Sandstone Group; Middle Triassic; Anisian) includes remains that were formerly attributed to a primitive procolophonid. In the light of new specimens, this material is instead found to contain remains of a diapsid and a procolophonine procolophonid. Among these fossils, the medium‐sized procolophonine, Kapes bentoni sp. nov., is the first record of this Russian genus in the British Triassic. Coartaredens isaaci gen. et sp. nov. is a small diapsid tentatively assigned to Lepidosauromorpha. The heterodont lower dentition of Coartaredens comprises a row of large, conical posterior teeth and tightly packed, procumbent incisiforms. Two additional specimens are distinguished on the basis of distinctive dentary remains. One of these is of possible procolophonid affinity, while the dentition of the second resembles that of the aberrant Early Triassic parareptilian genus Sclerosaurus.
A Revision of Early To Mid Ordovician Hyoliths from Sweden
Authors: Malinky John M.
Published: November 2003

Hyolith assemblages of early to mid Ordovician age in Sweden include the hyolithids Hyolithus bisulcatus Holm, H. concinnus Holm and H. innotatus Holm, which are confirmed as representatives of Hyolithes Eichwald. Dorsolinevitus Syssoiev is known from D. dispar (Holm), D. textilis (Holm) and D. vomer (Holm), and Carinolithes Syssoiev is represented by C. hospes (Holm) and C. triumvir (Holm). Sulcavitus caelatus (Holm), the type species that forms the basis for a family and even an order according to some, is redescribed; the order is suppressed. Hyolithus cymbium Holm is transferred to Stelterella gen. nov., and Theca crispata (Boll) is now the type species of Crispatella gen. nov. The unusual orthothecid Quadrotheca quadrangularis (Holm) is redescribed; the concept of Trapezotheca aemula (Holm) is emended, and Semielliptotheca dens (Holm) is transferred to Trapezotheca. Semielliptotheca Syssoiev is poorly known from only one species, S. rosmara (Holm), and that genus is now considered to be unrecognizable. Hyolithus exaratus Hadding is identified as closely related to the gastropod Lytospira norvegica Koken, and specimens of Hyolithus sp. nos 11, 12 and 13 Holm and Hyolithus sp. indet. Wiman, remain to be located.
Large Tristichopteridae (Sarcopterygii, Tetrapodomorpha) from the Late Famennian Evieux Formation of Belgium
Authors: Clement Gaël
Published: November 2003

Remains of two large sarcopterygians are described from Famennian deposits in Belgium. One of them is referred to Eusthenodon wängsjöi Jarvik; it is the first occurrence of this genus in Belgium. The other, much larger one, appears to be a tristichopterid. It has a postspiracular; size and shape of the mandible similar to those of Platycephalichthys skuenicus and P. bischoffi; snout and cheek patterns close to those of Eusthenodon; unusual shape of the supratemporal resembling that of Hyneria, Mandageria and Platycephalichthys skuenicus; and tooth histology quite similar to that of Eusthenodon and Platycephalichthys.
The Neurocranium of the Stereospondyl Mastodonsaurus Giganteus
Authors: Schoch Rainer R.
Published: November 2003

New and rich material of the stereospondyl amphibian Mastodonsaurus giganteus from Kupferzell in southern Germany allows for the first time a detailed study of the neurocranium of this species. Both sections and uncrushed specimens preserved in three dimensions were examined. The sphenethmoid ranges from the sella turcica region far to the anterior almost towards the nasal capsules, which remained unossified. The basisphenoid persisted as cartilage, whose morphology can be traced from imprints in surrounding bones. The otic is a single but complex element which underwent major ontogenetic changes. During development, the posterior braincase became increasingly ossified and finally formed a single, compound unit. In addition, otic and sphenethmoid are broadly co‐ossified in large specimens. The basioccipital is present but rudimentary, wedged in between the exoccipital and parasphenoid and without contribution to the occipital condyles. The course of the optic, trigeminal, and facial nerves is studied in detail. The homology of the passages is assessed by means of phylogenetic arguments and comparative anatomical data, based on observations on nearest living crown groups.
New Palaeomacromiid Dragonflies from the Upper Paleocene of Argentina
Authors: Petrulevicius Julián F. , Nel André
Published: November 2003

A new genus of palaeomacromiid dragonflies, Curviarculia, based on Curviarculia delicata sp. nov. and Curviarculia lamasi sp. nov., is erected from the upper Paleocene Maíz Gordo Formation of north–western Argentina. Phylogenetic relationships within Palaeomacromiidae are discussed, leading to a new family diagnosis.
The Middle Jurassic Bivalve ‘Cuspidaria’Ibbetsoni: A Corbulid Not A Septibranch
Authors: Harper Elizabeth M. , Palmer Timothy J. , Hudson John D.
Published: November 2003

A distinctive shallow–burrowing bivalve with an elongate rostrum, common in the British Middle Jurassic, is frequently referred to as Cuspidaria ibbetsoni (Morris, 1853) and as such is recognised as one of the earliest members of the anomalodesmatan family Cuspidariidae. Since modern cuspidariids are highly specialised bivalves and are voracious carnivores in the deep sea, whereas C. ibbetsoni is prevalent in brackish–water facies, questions have been raised over its true affinities. We have investigated new and pre–existing material of C. ibbetsoni, and have concentrated on shell microstructure, morphology, and musculature. Our findings suggest that the inequivalve shell is composed of crossed–lamellar aragonite rather than either homogeneous or prismato–nacreous structures. It also lacks the complex musculature associated with the raptorial siphon of the predatory septibranchs. These characters suggest that C. ibbetsoni should more properly be placed within the myoid family Corbulidae and a new genus, Rostrocorbula, has been erected to accommodate it. It has also been necessary to establish a neotype. The significance of this familial redesignation to our understanding of the evolution of carnivory within the Bivalvia is discussed.
Thelodont Scales from the Lower Devonian Red Bay Group, Spitsbergen
Authors: Blom H , Goujet D
Published: November 2003

Scales of nine thelodont taxa are described from the Red Bay Group of Spitsbergen, also characterized by its assemblage of other typical Early Devonian vertebrates. The four thelodont–bearing horizons of the lower Fraenkelryggen Formation yield typical Lochkovian thelodont assemblages, containing Boreania minima, Canonia grossi, Nikolivia depressa sp. nov., Nikolivia elongata, Nikolivia gutta and Turinia pagei. One horizon from the younger Ben Nevis Formation has a similar thelodont assemblage, except for two new taxa; Apalolepis angelica sp. nov. and Turinia barentsia sp. nov. The appearance of Turinia polita and the disappearance of Boreania minima is also characteristic for this assemblage. Comparison with similar faunas from the Northern Hemisphere supports this faunal change and allows further elaboration of Early Devonian thelodont biostratigraphy.
Fossil Seals from Late Neogene Deposits in South America: A New Pinniped (Carnivora, Mammalia) Assemblage from Chile
Authors: Walsh Stig , Naish Darren
Published: November 2003

A new monachine phocid pinniped assemblage from the north–central coast of Chile is described. The material was recovered from a marine bonebed of the Bahía Inglesa Formation which, based on macro– and microfossil evidence, is probably Late Miocene–Early Pliocene in age. At least two genera, Acrophoca and Piscophoca (both originally described from the Pisco Formation of Peru), are present. The Chilean material is significantly different from that of the two described species from the Pisco Formation and probably represents new species, though these are not named pending description of new material reported from Peru. The postcrania are morphologically intermediate between the northern Phocini and southern Lobodontini. The Bahía Inglesa Formation pinniped assemblage represents the first occurrence of fossil seals in Chile, and provides valuable information regarding the late Neogene radiation of monachines in the Southern Hemisphere. The occurrence of Acrophoca sp. in beds underlying a condensed Mio–Pliocene bonebed suggests that these strata are no older than Late Miocene.
A Stem Group Brachiopod From The Lower Cambrian: Support For A Micrina (Halkieriid) Ancestry
Authors: Holmer Lars E. , Skovsted Christian B. , Williams Alwyn
Published: November 2003

The shell structure of the Lower Cambrian Mickwitzia, a bilaterally symmetrical bivalve hitherto doubtfully assigned to the Brachiopoda, confirms that the genus shares characters with linguliform brachiopods. The columnar lamination of its organophosphatic shell is homologous with that characterizing acrotretides. The shell, however, is also pervaded by striated apatitic tubes indistinguishable from those permeating the sclerites of the problematic organophosphatic, laminar–shelled Micrina which is close to Halkieria. No crown group brachiopods have such tubes that are presumed to have contained setae. The presence of both these features in the Mickwitzia shell suggests that the stock is a stem group brachiopod with a halkieriid ancestry.
A Reappraisal Of Coletta Seca, A Basal Procolophonoid Reptile From The Lower Triassic Of South Africa
Authors: Modesto Sean P. , Damiani Ross J. , Sues Hans–Dieter
Published: November 2003

The skeletal structure of Coletta seca, a small procolophonoid reptile from the Lower Triassic Lystrosaurus Assemblage Zone of South Africa, is reconsidered in light of descriptions of other procolophonoids. The presence of a single row of relatively large, fang–like vomerine teeth, identified originally as the single autapomorphy of this taxon, is reinterpreted as two rows of parachoanal vomerine teeth that are similar in organization to those of coeval procolophonids from Russia. Coletta is distinguished from other procolophonoids by a complex tongue–and–groove suture between the anterolateral margin of the parietal and the posterolateral edge of the postfrontal, and by a transversely broad interpterygoid vacuity. The postfrontal in Coletta retains contact with the postorbital, as in basal taxa such as Owenetta, but it is restricted to the orbital margin, as in Procolophon and all other procolophonids. A phylogenetic analysis identifies Coletta as the sister taxon of the clade Procolophonidae. This phylogenetic position suggests that Procolophonoidea originated and diversified initially in Gondwana during the Permian, prior to Procolophonidae achieving a cosmopolitan distribution in the succeeding Triassic.
A New Carcinosomatid Eurypterid From The Upper Silurian Of Northern Vietnam
Authors: Braddy Simon J. , Selden Paul A. , Truong Doan Nhat
Published: November 2003

A new carcinosomatid eurypterid, Rhinocarcinosoma dosonensis sp. nov., and Hughmilleria sp., are described from the Dô Son Formation of the Dô Son Peninsula, northern Vietnam. R. dosonensis is characterized by podomere 7 of prosomal appendage VI produced into an anterodistal spine, a metastoma with a cordate posterior margin, and an indented opisthosomal differentiation (i.e. preabdomen–postabdomen margin is concave). The Dô Son Formation was originally interpreted as Late Devonian (Givetian/Frasnian) in age but the unit containing the eurypterid assemblage is now considered much older (Late Silurian). A deltaic palaeoenvironmental setting is interpreted from biotic associations and sedimentological evidence.
First British Mesozoic Spider, From Cretaceous Amber Of The Isle Of Wight, Southern England
Authors: Selden Paul A.
Published: November 2003

Cretamygale chasei, a new genus and species of spider, is described from a single specimen preserved in amber of early Barremian age from the Isle of Wight. This is the oldest (and second Cretaceous) amber spider to be described, and the first record of a Mesozoic spider from Britain. It belongs to the group Bipectina of the infraorder Mygalomorphae, and is tentatively referred to the family Nemesiidae. It is the oldest bipectinate, extending the record by around 90 myr, the only known fossil nemesiid, and the second oldest fossil mygalomorph.
Frenelopsis (Coniferales: Cheirolepidiaceae) And Related Male Organ Genera From The Lower Cretaceous Of Spain
Authors: Gomez Bernard , Martín–Closas Carles , Barale Georges , Solé de porta Núria , Thévenard Frédéric , Guignard Gaëtan
Published: November 2003

Vegetative plant remains and microsporangiate cones, related to the fossil genera Frenelopsis and Classostrobus respectively, were studied in three localities from the Lower Cretaceous of the Pyrenees and Iberian Ranges (Spain). Sterile remains belong to three different species: F. Rubiesensis Barale, F. Ugnaensis sp. nov. and F. Turolensis sp. nov. The male cones Classostrobus ugnaensis sp. nov. and C. Turolensis sp. nov. are associated with the two latter species respectively, and C. Turolensis is found in connection with F. Turolensis. Internodes of F. Ugnaensis display small hemispherical papillae and long conical hairs covering the entire cuticle surface, while F. Turolensis has a strip of hairs near the leaf margin, in addition to more massive outer stomatal papillae and higher stomatal density. The tiny cones of C. Ugnaensis bear microsporophyll cuticles capped with vermiculate flattened papillae and a fringe of marginal hairs, while C. Turolensis has a central area of microsporophylls covered by long conical hairs. Sedimentological and taphonomic analyses show that the assemblages studied belong to a wide spectrum of habitats. These indicate that Spanish Lower Cretaceous frenelopsids were xeromorphic plants, able to adapt to helophytic and riparian habitats, and grew in brackish coastal marshes and fluvio–lacustrine freshwater environments.
Sauropod dinosaurs from the Lower Cretaceous of eastern Asia: taxonomic and biogeographical implications
Authors: Barrett Paul M. , Hasegawa Yoshikazu , Manabe Makoto , Isaji Shinji , Matsuoka Hiroshige
Published: November 2003

Sauropod dinosaurs are poorly represented in the Lower Cretaceous of eastern Asia. Here, we describe a number of isolated sauropod teeth from the Kuwajima Formation (?Berriasian–?Hauterivian) of Shiramine, Japan. The mosaic of shared derived characters and symplesiomorphies displayed by the teeth indicate that they are referable to a basal member of the titanosauriform radiation. A taxonomic review of previously described sauropod specimens from eastern and south–eastern Asia reveals that a diversity of sauropods (including a titanosaurian, a basal titanosauriform and a ?euhelopodid, as well as several forms of indeterminate systematic position) was present in this region in the Early Cretaceous. This diversity conflicts with previous suggestions that eastern Asia was biogeographically isolated from the rest of Laurasia until the late Early Cretaceous and that the sauropod fauna was limited to the endemic East Asian clade Euhelopodidae. The presence of titanosauriform sauropods in the basal Cretaceous of Japan and Thailand indicate that the proposed faunal isolation of eastern Asia ended approximately 20 myr earlier than usually suggested.
Conulariid–like fossil from the Vendian of Russia: a metazoan clade across the Proterozoic/Palaeozoic boundary
Authors: Ivantsov Andrei Yu. , Fedonkin Mikhail A.
Published: November 2003

A conulariid–like fossil is described for the first time from Upper Vendian (late Neoproterozoic) deposits. Vendoconularia triradiata gen. et sp. nov. is found with other fossils in poorly cemented, siliciclastic deposits of the lower part of the Ust’–Pinega Formation, exposed in the middle reaches of the Onega River, north of the Russian Platform. This fossil assemblage, stratigraphically lowermost in the region, includes Swartpuntia Narbonne, endemic Ventogyrus Ivantsov and Grazhdankin, Calyptrina–like tubular forms, and other new, as yet undescribed, species. Vendoconularia is described here using morphological terms developed for conulariids owing to their striking similarity. However, the six faces of the conical test and three–fold symmetry may reflect some phylogenetic connection with the larger clade of Trilobozoa, a cnidarian class that radiated during the Late Vendian–Early Cambrian and then became extinct.
The brachiopod fold: a neglected body plan hypothesis
Authors: Cohen Bernard L. , Holmer Lars E. , Lüter Carsten
Published: November 2003

Attention is drawn to Nielsen’s radical body plan concept, here named the ‘brachiopod fold hypothesis’, under which brachiopods and phoronids are recognized to be transversely folded across the ontogenetic anterior–posterior axis so that, to make useful comparisons with other phyla, these organisms must be conceptually unfolded. Under the hypothesis brachiopod brachial and pedicle shell valves are respectively ‘anterior’ and ‘posterior’ rather than ‘dorsal’ and ‘ventral’ as traditionally described. The hypothesis makes sense of the symmetry axes of the brachiopod shell, is consistent with various indications from fossil and Recent brachiopods, and gives rise to predicted patterns of axis–determining gene expression that differ from those obtaining under the traditional view of the body plan, whilst the variety of folding movements in different lineages implies that superficially dissimilar morphogenetic folds may be fundamentally homologous. Convergent folding patterns are noted in some other organisms. A previous conjecture that inarticulate linguloid brachiopods were derived from halkieriid–like ancestors is elaborated with proposals that recognize possible functional continuities of coelomic and marginal sclerite functions, and it is noted that an ancestrally facultative fold could have become incorporated by genetic assimilation into the brachiopod developmental program. An experimental approach is outlined to test the possibility that some members of the ‘small shelly fauna’ may have been members of the halkieriid–like brachiopod stem lineage and it is also suggested that buoyancy modification may have been an important function of mineralization amongst Lower Cambrian floaters and swimmers, since negative buoyancy would facilitate access to the benthic niche.
Microscopic imprints on the juvenile shells of Palaeozoic linguliform brachiopods
Authors: Williams Alwyn
Published: November 2003

The juvenile shell of living discinid brachiopods is composed of valvular mosaics of rhombic, micrometric–sized siliceous tablets. The tablets are shed in adult growth stages leaving shallow imprints on the primary layer of the organophosphatic mature shell, which occur on an upper Silurian discinoid. Imprints also indent the first–formed shells of over 100 lingulate genera, including all acrotretides and Paterula. No micrometric bodies that could have made these imprints are known, but their structure and composition can be inferred from imprint morphology. Diagnostic features of imprints as casts include constancy of shape and size, and rigidity of the indenting bodies relative to the rheology of the polymerizing primary layer of chitin, glycosaminoglycans (GAGs) and apatite, in which they were embedded. Three kinds of discrete structures are distinguishable. Nanometric–sized, basinal pits that may be compound or deformed, are assumed to be casts of mucinous vesicles. Larger, flat–based and hemispherical imprints were almost certainly made by biomineralized discoids and spheroids. Additional evidence that discoids and spheroids were more soluble than apatite suggests that they were calcitic. Mineralized mosaics could have protected pelagic juveniles from solar radiation in the early Palaeozoic when the ozone layer was more rarified than today.
Morphology and biomechanical implications of isolated discocystinid plates (Edrioasteroidea, Echinodermata) from the Carboniferous of North America
Authors: Sumrall Colin D. , Parsley Ronald L.
Published: November 2003

Detailed examination of isolated thecal plates belonging to three discocystinid edrioasteroids, Spiraclavus nacoensis Sumrall, Hypsiclavus kinsleyi Sumrall, and Giganticlavus bennisoni Sumrall and Bowsher, reveals striking similarity in morphology among these species. Stereom observed in the ambulacral floor plates indicates that ligamentous connective tissue opened the ambulacral cover plates and muscle tissue closed them. The ambulacral floor plates are interpreted as rigid supports for the oral surface with the interambulacral areas acting as flexible integuments of plates. The aboral surface is interpreted as flexible and highly contractile. All discocystinid thecal openings are consistent in morphology with adaptations for thecal pressurization. Extension and contraction of the theca was accomplished by pumping water in and out of an inflatable sac associated with the periproctial opening. The pedunculate zone is interpreted as passively expanding and contracting by relaxing of mutable collagenous tissue and stiffening when the theca was in the desired position. All of these features illustrate that discocystinid edrioasteroids have highly–evolved morphology and function.
Functional aspects of the postcranial anatomy of the Permian dicynodont Diictodon and their ecological implications
Authors: Ray Sanghamitra , Chinsamy Anusuya
Published: November 2003

The postcranial skeleton of the Permian dicynodont Diictodon is described, major skeletal muscles restored and functional aspects of the skeleton analyzed. The humerus was caudolaterally oriented and articulated in a near sagittal plane. This reduced the transverse component of thrust during locomotion. Throughout the stride, the femur, which is relatively longer than the humerus, was held in a parasagittal position. Diictodon probably had a hindlimb gait similar to the high walk of crocodilians. Comparisons between several dicynodont genera, including Diictodon, reveal considerable variation in the limb orientations, articulations, posture and gait among these taxa. Expansion of the preacetabular iliac process and the overall iliac length with respect to its height among these dicynodonts may be correlated with the increase in the number of the sacral vertebrae. Diictodon does not show the cranial and forelimb modifications suitable for digging as seen in Cistecephalus, Kawingasaurus and extant burrowers such as a broad skull, rounded occiput for considerable neck musculature, a robust humerus and a prominent olecranon process. However, a cylindrical body, short limbs with well–developed limb elevators and depressors and a long wide manus with long, blunt claws probably helped in digging. In addition, the hindlimb with well–developed retractors and short, blunt claws participated in soil removal. The caudolaterally oriented humerus and a laterally flexible vertebral column facilitated movement in the narrow confines of the burrows. Forelimb articulation and morphology indicate that its method of digging was probably rotation–thrust, where humeral excursion and not forearm extension played a dominant role. The close associations of articulated paired skeletons of adult individuals suggest that Diictodon was gregarious. A large number of unconnected burrow–casts in a small area of about 500 m2, indicates that although the animals lived close together, they did not share a single large communal structure.
A survey of pathologies of large pterodactyloid pterosaurs
Authors: Bennett S. Christopher
Published: November 2003

Examples of four types of pathologies have been found on specimens of large pterodactyloid pterosaurs. Osteoarthritis of the intersyncarpal, carpometacarpal, or metacarpophalangeal joints, indicated by grooving of the articular surfaces in the direction of joint motion, is present on at least four pterosaur specimens from the Cambridge Greensand. This pathology has not been found in Pteranodon despite comparably large samples of specimens. Pteranodon most commonly exhibits deformed bones and lumps apparently resulting from injury, necrosis, and subsequent repair. A small number of pathological bone growths apparently not associated with injuries were found, as were healed fractures of a fourth wing phalanx and a pedal phalanx. The absence of healed fractures of other elements suggests that they were either uncommon or catastrophic and fatal. This study suggests that pathologies were not uncommon in large pterosaurs.
Protaspides of Leiostegium and their implications for membership of the order Corynexochida
Authors: Lee Dong‐Chan , Chatterton Brian D. E.
Published: November 2003

Protaspid morphologies of Leiostegium sp. aff. L. formosum from the Lower Ordovician Garden City Formation, western United States strongly support the inclusion of the Leiostegiina in the order Corynexochida. A similar metaprotaspid morphotype is present in the three suborders of the Corynexochida, the Corynexochina, Leiostegiina, and Illaenina, supporting their corynexochid membership.
Reconsideration of the supposed naraoiid larva from the Early Cambrian Chengjiang Lagerstätte, South China
Authors: Zhang Xing‐Liang , Han Jian , Zhang Zhi‐Fei , Liu Hu‐Qin , Shu De‐Gan
Published: November 2003

The Chengjiang Lagerstätte in the Lower Cambrian of South China yields a small, larva‐like arthropod, which was considered to be a protaspis of naraoiids by many authors. The discovery of a large number of well‐preserved specimens from many new localities has allowed the original study to be revised. The relatively large size, stable morphology and unusual structure of the appendages indicate that these specimens represent adults of a new arthropod, Primicaris larvaformis. The larva‐like outline is considered to have arisen by the heterochronic process of progenesis. In addition, this animal displays primitive aspects of bodyplan and limb morphology that suggest a basal position within arachnomorphs, or perhaps even arthropods, and the similarities to the Vendian arthropod‐like animal Parvancorina probably provide an evolutionary link between Vendian forms and Cambrian arthropods.
Upper Silurian microplankton of the Leintwardine Group, Ludlow Series, in the type Ludlow area and adjacent regions
Authors: Richards Ruth E. , Mullins Gary L.
Published: November 2003

The acritarchs and prasinophyte algae from the Upper Bringewood, Lower Leintwardine, Upper Leintwardine and Lower Whitcliffe formations of the Ludlow type area and surrounding regions are described. The following new taxa are proposed: Cymatiosphaera pumila sp. nov., Melikeriopalla pustula sp. nov., Cheleutochroa beechenbankensis sp. nov., Cymbosphaeridium molyneuxii sp. nov., Flammulasphaera bella gen. et sp. nov., Percultisphaera incompta sp. nov., Salopidium aldridgei sp. nov. and Umbellasphaeridium? wicanderi sp. nov. A holotype is defined for Lophosphaeridium galeatum Hill and a further 34 new taxa are described under open nomenclature. Two biozones, identified by the first appearance of the zone taxon, are defined in the Sunnyhill section, Ludlow [Global Stratotype Section and Point (GSSP) for the base of the Ludfordian Stage, Ludlow Series]. The base of the Leoniella vilis Biozone is identified at 4.52m below the top of the Upper Bringewood Formation at Beechenbank, Aymestrey. The base of the Triangulina sanpetrensis Biozone is identified at 15.49m above the base of the Lower Leintwardine Formation and Ludfordian Stage at the Sunnyhill section. These biozones allow correlation with sections in north–west Spain, Podolia and Gotland. The possibility of using Visbysphaera whitcliffense and U.? wicanderi as biozonal indicators is suggested.
Amphibian swimming traces from the Lower Permian of southern New Mexico
Authors: Braddy Simon J. , Morrissey Lance B. , Yates Adam M.
Published: November 2003

Fossilised traces of swimming amphibians, assigned to Batrachichnus delicatulus and Serpentichnus robledoensis igen. et isp. nov., are described from the Lower Permian of the Robledo Mountains, southern New Mexico. The B. delicatulus specimen is interpreted as a trackway of a small ‘amphibian’ (temnospondyl, nectridean, microsaur or juvenile embolomere) swimming straight ahead. S. robledoensis consists of repeated pes imprints separated by discontinuous, L‐shaped imprints (body traces). It is interpreted as a trackway of an ‘amphibian’ swimming in a similar manner to the motion of a side‐winding snake. The producer of S. robledoensis is more distinctive than in B. delicatulus, and is suggestive of the lysorophian Brachydectes. This is the first locomotory trace to be assigned to this ‘amphibian’ group.
Llanvirn (Middle Ordovician) echinoderms from Llandegley Rocks, central Wales
Authors: Botting Joseph P.
Published: November 2003

A diverse Llanvirn echinoderm fauna is described from nearshore volcanogenic sandstones of Llandegley Rocks, Builth‐Llandrindod Inlier, Powys. The fauna comprises six crinoids (including Cefnocrinus samgilmouri gen. et sp. nov., Iocrinus llandegleyi sp. nov.), three asteroids and one cystoid; at least two indeterminate crinoids and one asteroid represent undescribed taxa, but yielded insufficient material for formal description. Two complex radical root structures are among the oldest recorded examples. Preservation occurs as external moulds, often fully articulated, with fine details preserved through early marginal silicification. The high diversity of this site suggests that the significance of echinoderm palaeocommunities from nearshore areas of low preservation potential is underestimated.
Revision and re‐evaluation of the Early Jurassic dinosaurian ichnogenus Otozoum
Authors: Rainforth Emma C.
Published: November 2003

Otozoum moodii Hitchcock, 1847 is one of the classic Connecticut Valley ichnotaxa established by Edward Hitchcock between 1836 and 1865. The taxon is redescribed, and AC 4/1a re‐established as the holotype specimen. Otozoum minus and O. caudatum are synonymised with O. moodii. The syntypes of Kalosauropus pollex (nomen nudum) are described as O. pollex sp. nov. Cladistic, quantitative, and comparative methods of trackmaker identification suggest that Otozoum was made by a prosauropod dinosaur. In quantitative analyses, only those phalanges likely to contribute to footprint morphology were considered; claws were also excluded due to their highly variable styles of impression. Several diagnostic characters distinguish Otozoum from Brachychirotherium, Chirotherium, Batrachopus, Tetrasauropus, and Pseudotetrasauropus; these ichnotaxa are probably attributable to crurotarsan archosaurs. Otozoum is found primarily in Hettangian strata of the Hartford, Deerfield, and Fundy rift basins of eastern North America; it is also present in the Early Jurassic Navajo Sandstone (Colorado Plateau, USA) and Clarens Formation (Lesotho). The taxon is unknown in older strata; Triassic material previously referred to Otozoum (including O. grandcombensis) instead belongs in Pseudotetrasauropus. Correlation of sediments and comparison of faunal assemblages, particularly within the Newark Supergroup, suggest that the Otozoum trackmakers were restricted to arid environments.
Osteopygis (Testudines: Cheloniidae) from the Lower Tertiary of the Ouled Abdoun phosphate basin, Morocco
Authors: Hirayama Ren , Tong Haiyan
Published: November 2003

Osteopygis emarginatus Cope 1868 is described from the Lower Tertiary of the Ouled Abdoun phosphate basin, Morocco, on the basis of skulls and lower jaws. Osteopygis is a cosmopolitan turtle that had a wide geographical distribution during the Late Cretaceous and Paleocene. Osteopygis emarginatus is a very conservative species which crossed the Cretaceous/Tertiary boundary without major changes.
A new genus and species of fimbriid bivalve from the Kimmeridgian of the western Pontides, Turkey, and the phylogeny of the Jurassic Fimbriidae
Authors: Monari Stefano
Published: November 2003

A new lucinoidean genus and species, Cerkesia contiae gen. et sp. nov., from the Kimmeridgian carbonate platform deposits of the Çerkes area (western Pontides, Turkey), is described and placed in the family Fimbriidae. Morphological comparisons reveal similarities with Fimbria, Cyclopellatia and Sphaera. A phylogenetic analysis supports the monophyly of the family. Similarities between Cerkesia and Fimbria determine inclusion of these genera in the same clade. The unusual features characterizing Cerkesia closely relate it to Cyclopellatia. Sphaera belongs to a different clade and its similarities with Cerkesia are owing to convergent and plesiomorphic characters. Cerkesia was a slow and shallow burrower. The morphology of the anterior adductor scar suggests a mode of life comparable to that of Fimbria but other features indicate adaptive strategies typical of the Lucinidae. The associated fossils and facies reveal that Cerkesia lived in soft and sandy substrates of quiet and protected areas of the carbonate platform under stressful environmental conditions. The appearance of Cerkesia in the western Pontides marks the eastward expansion of a clade that developed principally in the European seas during the Late Jurassic while the Sphaeriola‐Sphaera clade was confined to the southernmost Tethyan margin.
The Early Silurian brachiopod Eocoelia from the Hudson Bay Basin, Canada
Authors: Jin Jisuo
Published: November 2003

Eocoelia akimiskii sp. nov. from the Lower Silurian (upper Telychian) Attawapiskat Formation of Akimiski Island, James Bay, Nunavut, is the first and oldest Eocoelia to be described from the Hudson Bay Basin, one of three largest inland basins of North America. The new species lacks dental plates, dental cavities, and marginal deflection or lip, which indicates a post‐Aeronian form of the well‐known Eocoelia lineage. In rib numbers, Eocoelia akimiskii falls between E. curtisi and E. sulcata, being closer to E. sulcata. In rib strength, however, the new species is more closely allied to E. curtisi. Although Eocoelia is currently assigned to the Rhynchonellida because of its lack of spiralia, several features (particularly the lack of a septalium, the presence of a unique notothyrial platform and cardinal process, and dense, free‐hanging fibrous growth frills) of the genus and other leptocoeliids are distinctly atypical of the rhynchonellides. The new species occurs in an inter‐reef, shelly packstone facies within the Attawapiskat Formation, which is characterized by coral‐stromatoporoid reefs with abundant, diverse, reef‐dwelling brachiopods and other shelly organisms. The close association of Eocoelia akimiskii with the Attawapiskat reefs supports a shallow subtidal (BA2) setting generally assigned to the Eocoelia Community. The reefs themselves, however, host an extremely abundant brachiopod fauna dominated by Pentameroides, Trimerella, Septatrypa, and Gypidula. Four species of Clorinda are also common elements of the reef‐dwelling brachiopods. This demonstrates that the concept of the classic Early Silurian level‐bottom brachiopod communities cannot be directly applied to reef‐dwelling brachiopod communities.
Swimming trace of a coelacanth fish from the Lower Keuper of south‐west Germany
Authors: Simon Theo , Hagdorn Hans , Hagdorn Magnus K. , Seilacher Adolf
Published: November 2003

Parundichna schoelli igen. nov., isp. nov. from the Middle Triassic (Ladinian) Lower Keuper of Rot am See (Baden‐Württemberg, Germany) consists of clusters of sigmoidal scratches symmetrically arranged in a plaited pattern. It is here interpreted as the swimming trace of a large coelacanth fish. In contrast to ichnospecies of Undichna there is no unpaired groove left by the tail fin. Instead, the sets of parallel scratches resulted from the pendulum motion of two pairs of appendages, the pectoral and pelvic fins, which acted in alternation, as in tetrapods. This strange mode of swimming is compared to films of modern Latimeria and to computer simulations; it probably corresponds to a particular foraging behaviour. The presence of fittingly‐sized coelacanths is documented in coeval carbonates (Alberti‐Bank) by disarticulated skeletal elements. Since the Lower Keuper represents a fluvial and estuarine facies of the receding Muschelkalk sea, we cannot be sure whether this trace was made in a marine or freshwater environment.
A new trace fossil from the Middle Cambrian of the Grand Canyon, Arizona, USA
Authors: Lane A. A. , Braddy S. J. , Briggs D. E. G. , Elliott D. K.
Published: November 2003

An unusual trace fossil from the Middle Cambrian Bright Angel Shale Formation of the Grand Canyon, Arizona, consisting of two rows of biserially opposed circular or oval depressions, with alternating symmetry, is described as Bicavichnites martini ichnogen. et ichnosp. nov. While specimens of this trace may represent the surface expression of a complex treptichnid‐like burrow system, it is more likely that they are the walking traces of a bilaterally symmetrical benthic animal. The large variation in external width within the trackways is inconsistent with an arthropod producer. The trackway morphology and presence of limb spur marks suggest that the trace maker may have been a lobopodian, a Cambrian relative of modern onychophorans.
A new aglaspidid arthropod from the Lower Ordovician of Wales
Authors: Fortey Richard A. , Rushton Adrian W. A.
Published: November 2003

A new genus and species of aglaspidid arthropod, Tremaglaspis unite, is described from the well‐known upper Tremadoc locality of Y Garth in North Wales, and compared with other Cambrian and Ordovician taxa. It is remarkable in having a large hypostome, a character shared with other primitive arachnomorphs.
Redescription of Holmia inusitata (Trilobita) from the Lower Cambrian of Scandinavia
Authors: Ebbestad J. O. R. , Ahlberg P. , Høyberget M.
Published: November 2003

Well‐preserved topotype material of Holmia inusitata Ahlberg and Bergstro¨m, in Ahlberg et al., from the Lower Cambrian of Lauselva, southern Norway, allows a redescription of the species. Intraspecific variation of characters, such as the expansion and relative length (sagittal) of the anterior glabellar lobe and the curvature and length of the ocular lobes, is shown. The species is, however, considered a typical member of Holmia. A discussion of character variation and distribution within species of Holmia further demonstrates a great degree of intrageneric variation. Thus, the newly erected Baltobergstroemia Lieberman is regarded as a subjective synonym of Holmia, since the differences between the two genera can only effectively be applied to the type species. The age of the succession with H. inusitata is not well constrained by regional lithological correlations or by an acritarch assemblage, and lacks the well‐differentiated faunas of the uppermost zones in the Lower Cambrian of Scandinavia. It is obvious that it must be older than the Holmia kjerulfi‐group Zone, and strata with H. inusitata are, therefore, maintained as a discrete zone underlying that zone.
The early Cambrian helcionelloid mollusc Anabarella Vostokova
Authors: Gubanov Alexander P. , Peel John S.
Published: November 2003

One of the oldest known helcionelloid molluscs, Anabarella Vostokova, is redescribed on the basis of type material from the lower Cambrian of north Siberia. Published records of the type species, Anabarella plana Vostokova, show a very wide range in morphology, but studies of variation through ontogeny and in taphonomy confirm assignment to a single variable species. Other described species are reviewed.
A METHODOLOGICAL COMPARISON OF PHOTOSYNTHETIC OXYGEN EVOLUTION AND ESTIMATED ELECTRON TRANSPORT RATE IN TROPICAL ULVA (CHLOROPHYCEAE) SPECIES UNDER DIFFERENT LIGHT AND INORGANIC CARBON CONDITIONS1
Authors: Carr Herman , Björk Mats
Published: November 2003

Gross oxygen evolution was compared with the electron transport rate (ETR), estimated from chl a fluorescence parameters on the common tropical green macro alga Ulva fasciata Delile with confirmatory carbon saturation curves from U. reticulata Forskål. Theoretically, the relationship between estimated ETR and gross oxygen evolution should be 4:1, that is, four electrons are transported through PSII for each molecule of oxygen evolved. However, deviations of the 4:1 relationship have previously been reported. Measurements were conducted with two commercially available and portable pulse amplitude modulated (PAM) chl fluorometers. We sought experimental approaches that minimize discrepancies between the two different measuring techniques of photosynthetic rates, both for in situ and laboratory conditions. Using fresh algal tissue for each of the different irradiances gave the best fit of gross oxygen evolution and ETR even at irradiances above light saturation, where large discrepancies between oxygen evolution and ETR are common. With increasing dissolved inorganic carbon (DIC) concentrations, there was a curvilinear response of gross oxygen evolution in relation to ETR. We therefore suggest to establish DIC saturation curves in the laboratory, oxygen evolution is probably the most relevant choice. Photorespiration could not readily explain a curvilinear response of O2 evolution and proportionally higher ETR at high irradiances. ETRs measured with the rapid light curve function of the PAM were compared with steady‐state rates of gross and net oxygen evolution, and the ETR was found to decrease at higher irradiances whereas oxygen evolution was constant.