recursal/Fanatic-Fandom huggingface dataset:
Dollocaris

Credit: Andrey Atuchin.

*Dollocaris* is an extinct genus of Thylacocephalan that lived in France during the Jurassic.

## Description

*Dollocaris* is about 20 centimeters long, and hid away in deep-water Jurassic reefs. *Dollocaris* is characterized by massive eyes, six long legs and a hard shell.

## Paleoecology

*Dollocaris* swam by beating its small clawed legs. *Dollocaris* must have been an ambush predator, due its slow swim speed. *Dollocaris* must have waited in deep-water reefs for prey to swim by, only to grab it with its claws, eat feed the prey to its mouth.

## References

http://www.eartharchives.org/articles/extinct-crustacean-dollocaris-was-all-eyes/
Atreipus

Atreipus-Grallator grade tracks from the Newark Supergroup. Credit: Piotrus on the Wikimedia Commons.

## Statistics

### Diet

Herbivorous?

*Atreipus* is an extinct ichnogenus of ornithopod dinosaur that lived during the Triassic in North America, Africa and Europe.

## Description

Not much is known of *Atreipus*, only that the tracks consists of three toed hind limbs, and bony forearms. The identity of this dinosaur remains unknown.

## Distribution

*Atreipus* lived in Germany, Italy, Morocco, Poland, and the United States: New Jersey, New York and Pennsylvania.

## Species

* *A. milfordensis*
* *A. metzneri*
* *A. sulcatus*
* *A. acadianus*

## References

* https://en.wikipedia.org/wiki/Atreipus
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=68367
Ailuropoda microta

Skull of Ailuropoda microta. Credit: Skye McDavid.

*Ailuropoda microta* is an extinct species of bear that lived in China from the Late Pliocene to the Early Pleistocene.

## Description

Before a skull was discovered in 2001 by Changzhu Jin, only teeth and mandibles had been recovered. However, this skull was only described in 2007. It likely represents the ancestor of the modern giant panda *Ailuropoda melanoleuca*. It lived in the late Pliocene to early Pleistocene in China, with its fossils having been found at Jinyin Cave in Guangxi Province. Analysis of tooth wear shows that its diet was at least primarily bamboo, like the modern giant panda. However, *A. microta* was much smaller than the modern giant panda, reaching only 1 meter in length. *A. microta* supports less specialized anatomy than its descendants, supporting the theory that *Ailurarctos* is the first in the panda lineage. It bears an endocast morphology more similar to *Ailuropoda baconi* and *Ailuropoda melanoleuca* than to *Ursus maritimus*; the absolute endocast is smallest in *A. microta*, with the cerebral volume and sulcal length/unit area similar to all three mentioned *Ailuropoda*.

## Classification

*A. microta* is the earliest representation of the lineage. It suggests this lineage is long-separated from bears, which is how modern *Ailuropoda* have grown to become completely herbivorous.

## Paleoecology

*A. microta* lived in lowland tropical forests. The moist environment *A. microta* existed was dominated by bamboo, living alongside *Stegodon* and *Gigantopithecus*. Like other herbivores in this environment, it also fed on bamboo based on wear on preserved teeth, with specialized muscle anchor points indicating an advantage for chewing. It lived after a global climatic deterioration.

*A. microta* was first thought to have lived alongside an enigmatic species named *Homo erectus wushanensis* in 1991, theorized to have been a descendant of *Homo habilis* with morphology similar to it and African *H. erectus*, which suggests a west-to-east sweep of *Homo erectus* in China. However, Russel Ciochon (2009) determined the mandibular fragment was actually of a pongine likely attributable to *Meganthropus*. This suggests the *Homo erectus* that did live in the reason did not actually come in contact with thick forest dwelling species like *A. microta* or *Gigantopithecus*, instead relying to the grasslands to hunt and live. In this area, Longgupo, it was contemporaneous with *Gigantopithecus*, *Sinomastodon*, *Equus yunnanensis*, monkeys, rhinoceros, beavers, bears and tigers. At this point, the Yangtze River had not yet formed.

## References

1. ↑ MNHN Museum Plaque
2. ↑ 2.0 2.1 https://en.wikipedia.org/wiki/Ailuropoda\_microta
3. ↑ https://www.pnas.org/content/104/26/10932
4. ↑ https://link.springer.com/article/10.1007/s00114-008-0419-3
5. ↑ https://www.reuters.com/article/us-panda-skull-idUSN1841336520070618
6. ↑ https://en.wikipedia.org/wiki/Wushan\_Man
7. ↑ https://www.travelchinaguide.com/river/yangtze\_attraction/little\_gorge/longgupo.htm
8. ↑ https://www.nature.com/articles/459910a
Boreopithecus

The Piltdown mandible.

*Boreopithecus* is a dubious genus of paninan hominid that lived in England during the Holocene.

## History

The genus was assigned to a mandible associated with the Piltdown cranium, a notorious hoax by Charles Dawson. The mandible is of a 500-year old orangutan with filed down teeth and some teeth replaced with those of a fossil chimpanzee's. Friedrichs assigned this jaw to a new genus, *Boreopithecus*, calling the skull *Eoanthropus*. Gerrit Miller also gave the jaw a new name, *Pan vet*. Both terms are not used anymore and *Boreopithecus* is often referred to without a species name. The Piltdown Man hoax was revealed because filing marks were found on the teeth via microscopy and the jaw was stained to appear aged.

## References

* https://www2.clarku.edu/faculty/djoyce/piltdown/map\_expose/pilt\_man\_RiseAndFall.html
* https://en.wikipedia.org/wiki/Piltdown\_Man
Botrioides

Botrioides (bottom) . Credit: Joschua Knüppe.

*Botrioides* is an extinct genus of trilobite that lived in Norway during the Ordovician.

## Paleoecology

*Botrioides* is thought to be a fast moving and free-swimming predator.

## References

* https://en.wikipedia.org/wiki/List\_of\_trilobite\_genera
* https://www.trilobites.info/ordasaphida.htm
* https://en.wikipedia.org/wiki/Trinucleidae
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=20366
Cuban somphospondylan

The Cuban somphospondylan is an unnamed and lost genus of sauropod that lived in Cuba during the Late Jurassic.

## Description

In 1949, De la Torre y Callejas reported a dinosaur 'humerus', and was loosely assigned *Apatosaurus* and *Brontosaurus*. It was later referred to as a camarasauromorph metacarpal. Since it is strongly curved, it was suggested to be the first or second metacarpal of a somphospondylan. It is bowed, which is present only on somphospondylans, including some basal titanosaurs. This is Cuba's first dinosaur. However, it was lost soon after discovery and has never been recovered.

## References

https://www.tandfonline.com/doi/full/10.1080/08912963.2019.1661406
Dineobellator

Credit: Sergey Krasovskiy.

*Dineobellator* is an extinct genus of dromaeosaurid that lived during the Late Cretaceous.

## Description

*Dineobellator* possessed greater flexion in its hands and feet, compared to other dromaeosaurs. *Dineobellator* also had a tighter grip in the manual unguals, and a greater mobility in the tails base. These features suggest that it was more adapted to a fast-moving predatory lifestyle.

Quill knobs are present on the lower arm, meaning *Dineobellator* bore feathers, an assumed feature of every dromaeosaur. The right hand of the holotype bears a gouge, which shows no evidence of healing. This was possibly caused by another individual, near or close to the time of death. The specimen also bears a single re-healed rib.

## Paleoecology

Dineobellator lived in a lush floodplain dotted with wetlands and gymnosperm forests. It coexisted with ceratopsians *Ojoceratops* and *Torosaurs*, hadrosaurus *Edmontosaurus* and *Kritosaurus*, ankylosaurs *Glyptodontopelta* and one indet., *Alamosaurus*, ornithopods *Thescelosaurus*, *Pachycephalosaurus* and some others that are not known as of now. The ecosystem also had apex predators *Tyrannosaurus* and *Quetzalcoatlus*.

Even in the presence of large tyrannosaurs, dromaeosaurs like *Dineobellator* likely filled out an active predatory niche. Other smaller theropods include *Ojoraptorsaurus*, ornithomimids, *Richardoestesia* and troodontids. The ecosystem *Dineobellator* lived in also included a wide array of mammals and fish.

## References

* https://www.nature.com/articles/s41598-020-61480-7
* https://www.inverse.com/science/meet-dineobellator
* http://www.sci-news.com/paleontology/dineobellator-notohesperus-08269.html
* http://novataxa.blogspot.com/2020/03/dineobellator.html
* https://www.kidsnews.com.au/animals/scientists-have-unearthed-a-fearsome-feathered-dinosaur-with-sharp-claws-and-a-telltale-scar/news-story/6e028bcacad71cb3bf7380fb15fcd2f3
* https://www.dailymail.co.uk/sciencetech/article-8156509/Newly-discovered-feathered-dinosaur-one-known-raptors.html
* https://www.researchgate.net/figure/Skeletal-reconstruction-of-Dineobellator-notohesperus-gen-et-sp-nov-SMP-VP-2430-with\_fig2\_340216705 [Skeletal Reconstruction]
Cloverly Albanerpetontid

The Cloverly Albanerpetontid is an unnamed genus of Albanerpetontid Amphibian that lived in the Early Cretaceous of Wyoming.

## Description

The taxon is known from a pair of fused frontals, right dentary, right premaxilla and right humerus. The researchers recovered it at the base of *Albanerpeton* *sensu lato* and suggested placing the genera *Shirerpeton and Wesserpeton* within the clade, however, the amount of variety we see within Albanerpetontidae suggests that it is reasonable to place 6 species of *Albanerpeton* within new genera. It is mostly distinguished through a defined fossa cubitus ventralis, a very blunt internasal process and a pronounced orbital margin of the frontal. It is among the most plesiomorphous of the North American lineage, having primarily radiated in Europe.

## Classification

this phylogeny was modified from Daza et al (2020):

## References

* https://www.tandfonline.com/doi/abs/10.1080/02724634.2021.2003372?journalCode=ujvp20
* https://en.wikipedia.org/wiki/Albanerpetontidae#cite\_note-:1-6
* https://naturalhistory.si.edu/sites/default/files/media/file/2013-murch-poster.pdf
Acrocanthosaurus

Before formal naming or identification, this organism was known as the following on this wiki:
**"Capitalsaurus"**

## Statistics

### Synonyms

"Acracanthus"
"Capitalsaurus"?
*Creosaurus potens*?
*Dryptosaurus potens*?

### Weight

5.7-7.25 metric tons (6.3-7.99 short tons)?

### Diet

Carnivorous

*Acrocanthosaurus* is an extinct genus of carcharodontosaurid dinosaur that lived in North America during the Early Cretaceous.

## Description

*Acrocanthosaurus* is monotypic, containing *A. atokensis*. It is found mostly in Oklahoma, Texas, and Wyoming, with teeth reported from Maryland, suggesting a continent-wide range.

## Classification

"Capitalsaurus" was discovered in January 1898 at the intersection of First and F Streets S.E. in the Distinct of Columbia, which has now been dubbed Capitalsaurus Court. It was unearthed during sewer work, where a single partial vertebra was named "Capitalsaurus". However, some think the remains are so incomplete, they may not be able to support a formal name. "Capitalsaurus" is now the official dinosaur of the District of Columbia (now Washington, D.C.). Some suggest that it can be called *Acrocanthosaurus*.

## Notable Specimens

* "EMB7UT": A suggested "fossil embryo" written on by C.E. Goo in the Petrified Embryology series, However, many dismiss this as a product of pareidolia.

## References

* https://en.wikipedia.org/wiki/Acrocanthosaurus
* https://petrifiedembryology.wordpress.com/petrified-embryology-volume-2-the-frozen-baby-dinosaurs-acrocanthosaurus-atokensis/
* https://twitter.com/Dino\_Dobrowski/status/1494660452558770176/photo/2
* https://palaeo-electronica.org/content/2018/2123-appalachia-biogeography
* https://naturalhistory.si.edu/research/paleobiology
* http://dml.cmnh.org/2002Feb/msg00175.html
* http://www.lexisnexis.com/hottopics/michie/
Aenocyon

Credit: Juan Gil on ArtStation.

*Aenocyon* is an extinct genus of canid that lived in the Americas during the Pleistocene.

## Classification

*Aenocyon* was first considered a synonym of the dire wolf, a large canid also from the Americas. However, the idea that the dire wolf should be transferred to the genus Aenocyon has surfaced in 2020, based on genetic factors, and published in 2021. The genome of the dire wolf shows that it belonged to a different lineage of canids, diverging earlier. This evidence supports the theory that the dire wolf should be transferred from the genus *Canis* and into a more suiting genus; Aenocyon.

Five genomes were analyzed between 13,000 and 50,000 years ago. They were likely morphologically similar to the 5.7 million-year split, and it is highly unlikely no gene flow was present between Aenocyon and North American grey wolves or coyotes, with the dire wolf evolving in isolation from these species.

Despite other North American canids evolving from Eurasia and colonizing recently, Aenocyon representing New World origins.

## Gallery

**Credit: Mexicanpaleontology on DeviantArt.****Credit: Julio Lacerda.****Credit: HodariNundu on DeviantArt.***Smilodon* and *Aenocyon* mounts at the Royal Ontario Museum.
**Credit: Clumsystiggy on DeviantArt.**
## References

* https://www.nature.com/articles/s41586-020-03082-x

* https://www.scientificamerican.com/article/dire-wolves-were-not-really-wolves-new-genetic-clues-reveal/
Craterosaurus

Credit: CisioPurple on DeviantArt.

*Craterosaurus* is a possibly dubious genus of stegosaurid dinosaur that lived in Sussex, England during the Early Cretaceous.

## Description

*Craterosaurus* may be a junior synonym of *Regnosaurus*, but since little is known of the species, it is hard to know for sure. Described in 1874 by Harry Seeley, SMC B.28814, mistaken as the base of the skull, were correctly identified by Franz Nopsca (1912) as a partial neural arch. The authors describing the animal believe that *Craterosaurus* is not a valid genus. It is known from the Woburn Sands Formation.

## References

https://en.wikipedia.org/wiki/Craterosaurus
Chuandianella

*Chuandianella* is an extinct genus of incertae sedis arthropod that lived in China during the Early Cambrian.

## History

*C. ovata* was discovered from the Atdabanian-aged Chengjiang biota and described in 1975. It was originally considered a specimen on *Mononotella*, which was reclassified under *Chuandianella* by Hou and Bergström (1991). Additional specimens found resemblance with *Waptia*, In 2022, it was rejected from Hymenocarina, and was considered an "upper stem-group arthropod" of uncertain standing.

## Description

Unlike *Waptia* specimens, it has 8 abdominal somites and biramous, undifferentiated limbs. Some consider this enough to separate *Waptia* as a genus.

## References

https://en.wikipedia.org/wiki/Chuandianella
Cynarctoides

Cynarctoides fossil.

*Cynarctoides* is an extinct genus of canid that lived in North America during the Early Oligocene to the Middle Miocene.

## Description

*Cynarctoides* has seven species recognized and had unusual dentition, implying a herbivorous or omnivorous lifestyle.

## Species

* *C. acridens*
* *C. emryi*
* *C. gawnae*
* *C. harlowi*
* *C. lemur*
* *C. roii*

## References

https://en.wikipedia.org/wiki/Cynarctoides
Avalonianus

*Avalonianus* is a dubious genus of archosaur that lived in England during the Late Triassic.

## Description

*Avalonianus* was first given the name *Avalonia* with no epithet, however the name *Avalonia* is preoccupied. The remains were first thought to be a prosauropod, but later analysis showed that the holotype was a chimera. The teeth came from a non-dinosaurian ornithosuchian (or an early theropod; needing evaluation) and remains of a prosauropod (renamed *Camelotia*). The only material belonging to *Avalonianus* is several lost teeth chimeras referred to Archosauria.

## References

https://en.wikipedia.org/wiki/Avalonianus
Bombinator

"B. meridonalis" fossil specimen found within baked clay.

*Bombinator* is a dubious genus of frog that lived in Eurasia.

## History

The genus is typically used to refer to the fire-bellied toad, although fossil specimens have been assigned. One of which was a *B. meridionalis* from the slope of Mount Epomeo, Italy found encased within volcanically-baked clay and described in 1864.

## References

* https://www.biodiversitylibrary.org/item/54640#page/495/mode/1up
* https://en.wikipedia.org/wiki/Fire-bellied\_toad
* http://www.fossilworks.org/cgi-bin/bridge.pl?a=taxonInfo&taxon\_no=363173
Aelurodon

*Aelurodon* is an extinct genus of canid that lived Early-Late Miocene in North America.

## Description

‬*Aelurodon* had bone-crushing jaws and was very similar to hyenas being an ancestor to *Protomarctus* and *Tomarctus*. *Aelurodon* hunted like wolves and has a very wide range of mostly the USA and other parts of North America.

## Species

* *A. asthenostylus*
* *A. ferox*
* *A. mcgrewi*
* *A. montanensis*
* *A. stirtoni*
* *A. taxoides*
Boletuoolithus

*Boletuoolithus* is an extinct, dubious oogenus of oviraptor egg that live in North America and Asia during the Cretaceous.

## Description

*Boletuoolithus* was described in 1998 by Bray, but has since become a dubious oogenus, being a synonym of *Macroelongatoolithus*.

## References

https://en.wikipedia.org/wiki/Macroelongatoolithus
Brevivulva

*Brevivulva* is an extinct genus of parasitic wasp that lived in Europe during the Early Eocene.

## Description

*Brevivulva* is preserved in a block of amber discovered in a Baltic mine. This insect has an ovipositor, metallic elements, and other features that modern wasps and *Brevivulva* share.

## Paleoecology

*Brevivulva* likely attacked woodboring beetles and other insects that have similar camouflage. The eggs would be injected into other arthropods, to which they would eat the host from the inside out, and emerge into the world.
Cratia

*Cratia* is an extinct genus of frog that lived in Brazil during the Early Cretaceous.

## History

*Cratia* is named after the Crato Formation, and was named by Ana M. Báez, Geraldo J.B. Moura and Raúl O. Gómez in 2009. The holotype, MPSC-Am 891, is a small, delicate individual that is 29 millimeters long (snout-vent).

## Description

It preserves the ribcage, the spine, limbs, hips and a skull. It is articulate, except for the skull which is somewhat disarticulated and shifted forward. The right half of the skull was weathered and preserves the ventral impression in the sediment. It is a possible juvenile that is postmetamorphic, based on ossified otic capsules, mentomeckelians and quadratojugals. The skull is proportionally large, rounded and slightly wider than long. An unknown amount of presacral vertebrae nd articulation is seen. The pectoral girdle is exposed in the dorsal and the right scapula is fully preserved. A poorly preserved radioulna and humerus are known. The right side fo the skeleton has 2 phalanges articulated with an incomplete metacarpal. The hips are known mostly from impressions and small fragments. Leal and Brito (2006) first placed the skeleton into *Arariphrynus placidoi* despite remarkable difference.

## References

* https://en.wikipedia.org/wiki/Cratia
* https://www.sciencedirect.com/science/article/abs/pii/S0195667109000056?via%3Dihub
Egoria

*Egoria* is an extinct genus of stem-salamander that lived in Siberia during the Middle Jurassic.

## Description

*E. malashichevi* is named after Yegor Malashichevi, in memory of the scientist. It was named from vertebrae (atlas centrum and a fragmentary trunk vertebral centrum, the latter formerly referred to as "Berezovsk salamander A”). The atlantal anterior cotyles have an elliptical anterior outline at an gle of 135-137°, a wide posterior of the atlantal centrum, the ossified part of the intercotylar tubercle has dorsal and ventral lips, there is no deep depression on the ventral of the atlantal centrum, no pronounced ventrolateral ridges at the atlas, no spinal nerve foramina, a pitted texture on the ventral and lateral surfaces of the central and lateral surfaces of the neural arch pedicels, a short atlantal neural arch with an anterior border that is behind thelevel of the anterior cotyles, short trunk vertebrae and a larger diapophysis than the parapophysis, with the notochordal canal opening at the upper half of the cotyle are all distinguishing traits. The micronanatomical organization of the atlas and trunk vertebrae is characterized by the endrochondral. The small body size idnicates that not all salamanders were large and neotenic, hinting to a broader ecology for stem forms.

## References

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7029856/
Arostropsis

*Arostropsis* is an extinct genus of weevil from the Late Eocene in the Baltic Region.

## Description

The animal appears to be a metallic green. This weevil is much like modern weevils. The specimen is comprised of one male who is 6.4 millimeters long and 1.3 millimeters tall. *Arostropsis* has a small head and other defining features.

## References

https://en.wikipedia.org/wiki/Arostropsis
Crossochelys

Credit: Armin Reindl on the Wikimedia Commons.

*Crossochelys* is a dubious genus of turtles that lived in Argentina during the Middle Eocene.

## Description

Comparing the neotype of *Niolamia* and the holotype, it is possible to identify that AMNH 3161 was very young at death and less than 4x smaller than the adult. The horns were much smaller at this stage of ontogeny. Scales A were separate during this stage and would have fused later in life; the former state was first listed as a diagnostic trait. Scales X reach down through the G scales like derived genera (*Ninjemys*, *Warkalania*) and unlike *Niolamia*. The presence of this trait into adulthood later in the clade suggests that it became pedomorphic. A "true temporal fenestra" was also included as a diagnostic trait, but the spot would have fully closed and sutured as the animal grew.

## Classification

*Crossochelys* was originally thought to be a different genus, compared with the similar *Meiolania* and *Niolamia*. *Crossochelys*, alongside the rest of Meiolaniidae. The analysis concluded that *Crossochelys* and *Niolamia* were the same, and combined into one genus; *Niolamia*. The holotype was once AMNH 3161, a juvenile skull. Gaffney (1996) was convinced that Simspon (1938)'s taxon was a juvenile, making it a junior synonym; Sterli and de la Fuente (2011b) agreed with this sentiment, with their analysis focusing on a newly-prepared skull and novel characteristics to include in taxonomic discussion.

## References

* https://en.wikipedia.org/wiki/Niolamia
* https://bioone.org/journals/journal-of-vertebrate-paleontology/volume-31/issue-6/039.031.0618/Re-Description-and-Evolutionary-Remarks-on-the-Patagonian-Horned-Turtle/10.1080/039.031.0618.short
* https://bioone.org/journals/bulletin-of-the-peabody-museum-of-natural-history/volume-56/issue-1/014.056.0102/A-Review-of-the-Fossil-Record-of-Gondwanan-Turtles-of/10.3374/014.056.0102.short?tab=ArticleLink
Borophagus

Credit: Roman Uchytel.

*Borophagus* is an extinct genus of borophagine canid that lived in North America from the Middle Miocene to the Late Pliocene.

## Description

*Borophagus* has a bulging forehead and powerful jaws. Once considered a scavenger, it's premolars and jaw muscles had the capability to break bone. Since it was so dominant, it is thought to have been an apex predator, since carrion could not have supported a population as large as what is known. Authors also note the bone crushing is a feature in scavengers, interpreting it as a social hunting adaptation where all of a carcass was used. Coprolites support the bone crushing theory, also indicating *Borophagus* inhabited a niche no longer present in North America. It may have been social and a pack hunter. Adults were 80 centimeters long, similar to a coyote, but also much more robust.

## Classification

*Borophagus* and other borophagines are known as "bone-crushing" or "hyena-like dogs". Although *Borophagus* was not the largest borophagine, it was more adapted to crushing bone than later genera, such as *Epicyon*. This is seen as an evolutionary trend. The genus began being displaced by species such as *Canis edwardii* and *Aenocyon dirus*. Early species were once placed in *Osteoborus*, but were recently reclassified.

## Paleoecology

Borophagus as contemporaneous with *Agriotherium*, *Barbourofelis*, *Amphimachairodus coloradensis* and *Epicyon* in places such as Coffee Ranch, Texas. They were all predators who may have competed with Borophagus for resources. It preyed upon *Aepycamelus*, *Cosoryx*, *Neohipparion*, *Nannippus*, *Prosthennops* and *Teleoceras*. All may have been accessible through hunting or scavenging.

## Species

* *B. diversidens*
* *B. dudleyi*
* *B. hilli*
* *B. littoralis*
* *B. orc*
* *B. parvus*
* *B. pugnator*
* *B. secundus*
* *Dinocyon (B.) meandrinus*

## Synonyms

* *Cynogulo*
* *Hyaenognathus*
* *Porthocyon*
* *Osteoborus*
* *Pliogulo*

## References

* https://en.wikipedia.org/wiki/Borophagus
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=41196
Cladoselache

*Cladoselache* is an extinct genus of sharks that lived during the Late Devonian in North America.

## Description

*Cladoselache* shows many ancestral and derived traits. Some of which are similar to extant mackerel sharks due to similar ecology. Its body is streamlined with 5-7 gill and a short, rounded snout with a terminal mouth located on the front rather than underneath. The jaws could not open very wide. Compared with modern sharks, its jaw joint is very weak. It compensated that, however, with very strong jaw-closing muscles. The teeth are multi-cusped and smooth-edged, suitable for grasping but not tearing or chewing. Thus, *Cladoselache* likely seized prey tail first, swallowing them whole. The fin spines were sturdy but lightweight . A blade-like structure sat on the anterior of the dorsal fins. These eased swimming and made it faster. Unlike most sharks, *Cladoselache* lacked scales, except for small-cusped scales on the edges of the fins, mouth and eyes Powerful keels extended to the side of the tail stalk and a semi-lunate tail fin, having a superior lobe near to the same size as the inferior. These helped with speed and agility, which helped *Cladoselache* outswim predators such as the much larger *Dunkleosteus*. Structures around the eyes are sometimes interpreted as denticles surrounding the eye or as sclerotic ossicles, but recent discoveries of denticles on the eyes of whale sharks could pose a solution, though it is unknown what these structures in *Cladoselache* are made of since they have not been histologically examined. This may be supported by ecology, but more study is required.

## Paleobiology

*Cladoselache* were predators, as well-preserved specimens from Cleveland revealed. Within the gut of these specimens were stomach contents, including shrimp-like arthropods and hagfish-like proto-vertebrates. Some fish remains found in the gut were preserved tail-first, further indicating this fish was fast and agile. Reproduction, however, it more of a mystery. It lacked claspers. This is strange since all sharks have these. Whether it used internal fertilization is unknown.

## Species

* *C. acanthopterygius*
* *C. brachypterygius*
* *C. clarki*
* *C. desmopterygius*
* *C. fyleri*
* *C. kepleri*
* *C. magnificus*
* *C. newmani*

## Reference

* Dorling Kindersley Encyclopedia of Dinosaurs and Prehistoric Life, p. 44
* https://en.wikipedia.org/wiki/Cladoselache
* https://twitter.com/EmuLarge/status/1482261030524923904
* https://twitter.com/TylerGreenfieId/status/1482219242485395456
Archelon

Credit: Futaka Kouhei‬.

*Archelon* is a genus of turtle that lived in North America during the Late Cretaceous.

## Description

*Archelon* shells have a well developed plastron and a poorly developed carapace. *Archelon* is the largest turtle known to have existed, weighing 220 kilograms (4900 pounds) and having 400 centimeters between each flipper. It had a very large, pronounced beak used for catching slippery marine fauna.

## Paleobiology

### Diet

*Archelon*'s main food source would have comprised of the nautilus, squid, fish and probably jellyfish. *Eutrephoceras*, a nautilus that lived in the Western Interior Seaway with *Archelon* may have been a frequent meal for the large turtle.

## Classification

*Archelon*'s closest relative was once thought to be the leatherback sea turtle, but has since been reevaluated to *Protostega*, a turtle that sits next to *Archelon* in a clade.
Balistes crassidens

*Balistes crassidens* is an extinct species of triggerfish that lived in Matanzas, Cuba during the Miocene.

## References

* http://fossilmatter.blogspot.com/2019/02/new-fossil-records-of-triggerfish-from.html
* https://www.researchgate.net/publication/331354850\_First\_occurrence\_of\_fossil\_Balistes\_Tetradontiformes\_Balistidae\_from\_the\_Miocene\_of\_Cuba\_with\_the\_description\_of\_a\_new\_species\_and\_a\_revision\_of\_fossil\_Balistes
Carcharodon plicatilis

*Carcharodon plicatilis/xiphodon*, known as the giant white or broad white shark (sometimes placed in *Isurus*, *Cosmopolitodus* or as a broad form of *Carcharodon hastalis*), is a proposed extinct species of shark that lived in the Americas, Europe, Asia and Australia from the Late Miocene to the Pliocene.

## History

*C. plicatilis* is among the most debated paleontological shark names. It was first described as *Isurus hastalis*, where a broad and narrow form were differentiated. Material assignable to *C. plicatilis* is the broad form. From the late 1980s to the early 2000s, it was found to be closer to extant *Carcharodon*, and should be included in such lineage. Glukman (1964) resurrected *Cosmopolitodus* to house it. Purdy (1996) found differences between both forms, using *C. xiphodon* for the broad form. Ward and Bonavia (2001) assigned it a nomen dubium since it lacks a holotype, among other issues. Whitenack and Gottfried (2010) supported the prior designation, but moved it to *Carcharodon*, since they had a close relationship. Ehret et al. (2012) rejected xiphodon and the "broad form", instead assigning it to *Carcharodon hastalis* as a sexual dimorphic form. Cione et al. (2012) then found many differences between forms, rejecting *xiphodon*, instead using Agissiz (1843)'s *C. plicatilis*. As of now, the state of this supposed species differs by opinion.

## Description

*C. plicatilis* is often considered the largest *Carcharodon*, sometimes called the broad white shark or the giant white shark. Teeth are often over 3 inches long, just larger than the great white. If distinct and valid, it diverged from *Carcharodon hastalis* during the Late Miocene or Early Pliocene. It went extinct by the end of the Pliocene alongside many other large sharks. Fossil teeth are found nearly global, but is exceptionally popular from the Yorktown Formation.

Occurrences from the Miocene Calvert Cave were once reported, but were suggested to be left for a different designation since they have broad crowns, the lack of distinctive features in small individuals and lacking lateral teeth in large individuals. Otherwise, the species can be identified by a very wide, triangular crown that is smooth with enamel stretching down to the root. The roots are shorter and less robust than *Carcharodon hastalis*.

## References

https://www.fossilguy.com/gallery/vert/fish-shark/giant-white/index.htm#plicatilis
Comanchesaurus

Credit: Clumsystiggy on DeviantArt.

*Comanchesaurus* is a naked genus of Saurischian Dinosaur that lived in New Mexico during the Late Triassic.

## Description

*Caomanchesaurus* is known from NMMNH P-4569; vertebrae centra and hindlimbs from Norian Bull Canyon Formation of Guadalupe County. Adrian Hunt proposed "*C. keusi*", a name never adopted, in a dissertation, which was mentioned in Nesbitt, Irmis and Parker (2007)'s redescription of Late Triassic North American fossils. They mentioned the remains belonged to a possible indeterminate Saurischian.

## References

https://en.wikipedia.org/wiki/List\_of\_informally\_named\_dinosaurs
Balochisaurus

Credit: Cisiopurple on DeviantArt.

"Balochisaurus" is a naked genus of titanosaurid sauropod dinosaur that lived in Pakistan during the Late Cretaceous Period.

## Description

A team from the Geological Survey of Pakistan discovered the remans near Vitariki, and named by M. S. Malkani in 2006 based on 7 tail vertebrae of the Vitakri Member of the Maastrichtian Pab Formation. Later, several more vertebrae and a skull was assigned "Balochisaurus". It was put into "Balochisauridae" with Marisaurus, then combined into Saltasauridae.

## References

https://en.wikipedia.org/wiki/List\_of\_informally\_named\_dinosaurs
Changdusaurus

*"Changdusaurus"* (also spelt *"Changtusaurus"*) is a naked genus of Stegosaurid dinosaur that lived in China during the Late Jurassic.

## Description

*"Changdusaurus"* is now labelled as an indeterminate member of Stegosauridae. Zhao (1986) informally named "*C. laminoplacodus*", but no description was ever given. Once source states the material has been lost.

## References

https://en.wikipedia.org/wiki/List\_of\_informally\_named\_dinosaurs
Dzharatitanis

Credit: Andrey Atuchin.

*Dzharatitanis* is an extinct genus of sauropod dinosaur that lived in Uzbekistan during the Late Cretaceous.

## Description

The species name is named from Christopher King, who aided in Cretaceous geology from Asia. *Dzharatitanis* is among the youngest and first rebbachisaurids from Asia. These populations may have migrated from Europe during the Early-Middle Cretaceous. Alongside an indeterminate titanosaur, *Dzharatitanis* is one of the two sauropods known from the Bissekty Formation. *Dzharatitanis* was found in 1997 by Hans-Dieter-Sues and David J. Ward on the URBAC (Uzbek/Russian/British/American/Canadian) expedition. The remains were only named in 2021 by Hans-Dieter-Sues and Alexander Averianov, however. The genus was named by the Dzharakuduk locality and the Greek titans. The genus was erected from USNM 538127, an anterior caudal vertebra, likely the first in the series. They were originally described as Titanosauria indeterminate.

## Classification

Phylogenetic analysis recovered in 2021 shows that *Dzharatitanis* is a rebbachisaurid with a currently unresolved polytomy with *Demandasaurus*, *Nigersaurus*, *Rayososaurus* and *Rebbachisaurus*.

## References

https://en.wikipedia.org/wiki/Dzharatitanis
Chingkankousaurus

Credit: Maya Jade McCallum.

*Chingkankousaurus* is a dubious genus of Tyrannosauroid that lived in China during the Late Cretaceous.

## Description

*Chingkankousaurus* is known from a single bone fragment discovered in China, and identified as part of a scapula later. The fragment was described as "basically resembles that of *Allosaurus* but is smaller". The fragment was then proposed to be from a rib or part of the gastralia, which was considered unlikely in a study from 2013. The scapula was assigned to Coelurosauria, then Tyrannosauroidea, where it is now classed as a nomen dubium.

## Notable Specimens

* IVPP V636: The holotype of *Chingkankousaurus*, thought to have been a rib or gastralia, but turned out to be a scapula.

## References

https://en.wikipedia.org/wiki/Chingkankousaurus
Cellicalichnus

*Cellicalichnus* is a extinct ichnogenus of sweat bees that lived in Patagonia during the Early Cretaceous.

## Description

*Cellicalichnus* represents a diversification of seat bees at the same time as angiosperms 100 million years ago. It is a typical halictini nest, having sessile cells connected to main tunnels. Geological, paleosol, paleobotanical and ichnological data shows these bees and angiosperms lived inland in an open, dry woodland or savanna, with a warm temperature and semiarid-subhumid climate in the Albian southern hemisphere.

## References

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0227789
Edmontonia

Credit: Jack Wood.

*Edmontonia* is an extinct genus of nodosaur that lived in Canada during the Late Cretaceous.

## Description

*Edmontonia* is a bulky nodosaur known from many fossils and a single well-preserved mummy representing the genus. *Edmontonia* was adorned with many osteoderms. The lower back/upper neck has large plat-like osteoderms in rows. Just above the fore legs are around four spikes, reaching their largest sizes in the center, with smaller sizes on the outside. The middle back is littered with medium/small osteoderms in long rows along the back and tail. Edmontonia had a flat beak, which is designed for snipping tough foliage from the undergrowth. *Edmontonia* did not have a tail club like popular ankylosaurs, like *Ankylosaurus* and *Euoplocephalus*. *Edmontonia*'s skull is relatively boxy, and shaped like a pear. *Edmontonia* is generally distinguished from similar genera due to minor skeletal differences, and osteoderm orientation.

## Classification

*Chassternbergia*, an extremely likely synonym, was once considered a subgenus of *Edmontonia*. In 1971, Walter Coombs referred to *Edmontonia* as a subgenus of *Panoplosaurus*. Little evidence supports this theory.

## Paleoecology

*Edmontonia* lived in the Edmonton Formation, hence the etymology, which is now known as the Horseshoe Canyon Formation. The rock formation shows evidence of seasonal shifts of precipitation and temperature, which may be a reason why some of the areas fossils are exceptionally preserved. The *Edmontonia* mummy may have died, dried out and been covered quickly in sediment as the rain season begun.

*Edmontonia* also lived in the Dinosaur Park Formation, a rich habitat during the Late Cretaceous Alberta. Several animals *Edmontonia* lived with include: *Edmontosaurus*, *Saurolophus* and *Hypacrosaurus*, a variety of freshwater and saltwater fishes and reptiles, troodontids, pachycephalosaurs, other ankylosaurs, dromaeosaurs, caenagnathids, ceratopsians and ornithomimids. *Edmontonia* was likely a low-browser, plucking plants from the ground. *Edmontonia* may have defended itself by charging into its predators, and hitting them with its tail, impaling the animal and leaving deep puncture wounds. The Horsheshoe Canyon Formation was ruled by mature *Albertosaurus*, with smaller niches filled with juvenile individuals.

## Notable Specimens

* AMNH 5665: A mounted skeleton, preserving fine scale detail and osteoderm placement on the back of *Edmontonia*. The skeleton consists of a partially-preserved front half.
* AMNH 5381: A well preserved mummy, consisting of a skull, neck, and lower back. The mummy shows the position of the osteoderms in life, as well as the scales. In 1922, the mummy was described as *Palaeoscincus* by Matthew.
* NMC 8531: The holotype of *Edmontonia* consisting of a skull, lower jaw, and several elements of the postcranial skeleton.

## References

* https://en.wikipedia.org/wiki/Edmontonia
* https://archive.org/details/g.s.paul2016theprincetonfieldguidetodinosaurs/page/n258/mode/1up
Coelophysis

Credit: Gabriel Ugueto.

*Coelophysis* is an extinct genus of Coelophysid Theropod dinosaur that lived in North America and Africa during the Late Triassic.

## Synonyms

* *Podokesaurus?*
* *Longosaurus*
* *Rioarribasaurus*
* *Gojirasaurus?*
* *Camposaurus?*
* *Megapnosaurus?*
* *Coelurus bauri (=C. bauri)*
* *Tanystropheus bauri (=C. bauri)*
* *Coelurus longicollis (=C. bauri)*
* *Tanystropheus longicollis (=C. bauri)*
* *C. longicollis (=C. bauri)*
* *Longosaurus longicollis (=C. bauri)*
* *Tanystropheus willistoni (=C. bauri)*
* *C. willistoni (=C. bauri)*

## References

* https://en.wikipedia.org/wiki/Coelophysis
* https://archive.org/details/g.s.paul2016theprincetonfieldguidetodinosaurs/page/n87/mode/2up
CPC 279

CPC 279 is an unnamed genus of chasmosaurine ceratopsian that lived in Mexico during the Late Cretaceous.

## Description

CPC 279 is a partial right squamosal found near Town Rincón Colorado, General Cepeda, in Coahuila. Loewen et al. (2010) described CPC 279, and it was concluded it was likely a new taxon. It lived during the Late Campanian.

## References

http://revistas.igme.es/Boletin/2015/126\_1/8-Articulo%204.pdf
Aliuslater

"Aliuslater" is a naked genus of actinopterygian fish that lived in Iowa during the Late Carboniferous.

## Description

Daniel Snyder (2006) named it in a thesis, stating it bears an unusual upper jaw, which is enough it erect a new genus. The genus translates to "another brick" and the species epithet, "in the wall", which is a reference to the song "Another Brick in the Wall" by Pink Floyd. Additionally, the genus "Floydus" was named in the same thesis after Pink Floyd. However, since it was named in a thesis, it is a nomen nudum. It was found in the Jasper Hiemstra limestone quarry.

## References

https://ir.uiowa.edu/cgi/viewcontent.cgi?article=1239&context=etd
Alcovasaurus

Before formal naming or identification, this organism was known as the following on this wiki:
**"Natronasaurus"**

## Statistics

### Synonyms

*Stegosaurus longispinus*
*Miragaia longispinus*?
*"Stegosaurus" sulcatus*?
"Natronasaurus"

### Diet

Herbivorus

*Alcovasaurus* is an extinct genus of stegosaur that lived in Wyoming during the Late Cretaceous.

## Description

*Alcovasaurus* is differentiated by long spines along its back, distal caudal vertebral centra which are rounded in both the anterior and posterior views, vestigial transverse processes on the distal caudal vertebrae, and centra with dorsal extensions that look like mushrooms. The two tail spines are slender, and very elongated, unlike most other stegosaurs. The spikes are as large as 90% of the thighbone, which is about 1082 millimeters long. The longest spike is 86 centimeters long.

Some scientists interpret the elongated spines and large muscle anchor point at the end of the tail as part of a defense mechanism. The strong muscles needed to be able to swing the heavy tail at oncoming predators. The tail was unusually short, compared to *Stegosaurus*. Other hypotheses say that *Alcovasaurus* had short caudal vertebrae, to support strong muscles.

Tyler Greenfield proposes *"Stegosaurus" sulcatus* is a dacentrurine due to similar dermal spines. Thus, the species "*sulcatus*" would make the Morrison dacentrurine *Alcovasaurus*/*Miragaia sulcatus*.

## Classification

"Natronasaurus longispinus" was described in 2014 by amateur paleontologist Roman Ulansky. The paper was self-published in an electronic publication, which was not archived by any independent organization, and, in tern, was not given an official ISSN. This lack of serial number makes the name invalid. In 2016, Peter Malcolm Galton and Kenneth Carpenter gave the genus a new name; *Alcovasaurus*.

## Notable Specimens

* UW 20503 D54: 42 vertebrae, a sacrum, two ischia, part of a pubis, a right femur, several ribs and four tail spikes, the holotype of *A. longispinus*.

## References

1. ↑ 1.0 1.1 https://twitter.com/TylerGreenfieId/status/1427333182966226944
2. ↑ 2.0 2.1 https://en.wikipedia.org/wiki/Alcovasaurus
3. ↑ http://www.paleofile.com/Dinosaurs/Armor/Natronasaurus.asp
Cynarctus

*Cynarctus* is an extinct genus of extinct canid that lived during the Middle to Late Miocene in North America.

## Description

*Cynarctus* was omnivorous and lacked the bone-cracking capabilities, similarly to related genera.

## Species

* *Cynarctus saxatilis*
* "C, acridens"
* *C. crucidens*
* "C. fortidens"
* *C. galushai*
* *C. marylandica*
* *C. voorhiesi*
* *C. wangi*
Dolichosuchus

*Dolichosuchus* is a possibly dubious genus of Coelophysoid that lived in Germany during the Late Triassic.

## Description

The holotype of *Dolichosuchus* is a single tibia, originally classified as a Crocodylomorph, and later moved to Coelophysoidea. Since it is known only as a tibia, it is considered dubious, some noting that it resembles that from *Dilophosaurus* and *Liliensternus*.

## References

https://en.wikipedia.org/wiki/Dolichosuchus
Cretogerris

*Cretogerris* is an extinct genus of waterstrider that lived in France during the Early Cretaceous.

## Description

*Cretogerris* resembles modern waterstriders, long, spindly legs with padding, and a reduced body. *Cretogerris* may have been detritivorous, or carnivorous.

## Clasification

*Cretogerris* was one of the first members of Gerridae, also known as waterstriders.

## References

https://dinopedia.fandom.com/wiki/Cretogerris

Image credit
CM 9401

CM 9401 in the lateral and medial views, respectively.

CM 9401 is a hypothetically unnamed genus of tyrannosaurine dinosaur that lived in Montana during the Late Cretaceous.

## History

CM 9401 was collected by John Bell Hatcher in 1903 from what was thought to be the Judith River Formation. However, analyses assigned CM 9401 to the Willow Creek Formation, Fergus County, Montana. In 2022, David Evans teased that work was being done on this specimen.

## Description

 File:CM 9401 skeltal.png
CM 9401 is a massive right lacrimal ~75 million years old, referred to ?*Tyrannosaurus sp.* by Michael Urban and Matthew Lamanna (2006). The lacrimal appears to lack a horn entirely. Certain features, such as a rugosity running along the dorsal that is very pronounced at the apex and appearing more inflated, is not seen in *Tyrannosaurus* or even *Tarbosaurus*. Thus, it has been tentatively referred to the former. However, if the Campanian age is true, since much of the discovery data is unknown because Hatcher's field notes were lost, this would make it the oldest occurrence of *Tyrannosaurus*. However, some find this to be unlikely, since most dinosaurs would not have this far of a temporal timespan (~10 million years estimated for *Tyrannosaurus*). Thus, there may be some potential for splitting CM 9401 into a new taxon. It was also suggested to be a new species of *Tyrannosaurus* or at least a closely-related taxon due to temporal range, but this was left a hypothesis in 2006.

## Paleoecology

CM 9401 lived in the Willow Creek Formation, which is known to straddle the K-PG boundary in some spots. However, CM 9401 is known from the Campanian. 10 million years prior to the mass extinction that took place at the end of the Maastrichtian. Willow Creek is also reported in western Canada along the Willow Creek tributary of the Oldman River. In this formation, it was contemporaneous with *Montanoceratops* and hadrosaurids. Additionally, many dinosaur egg fragments are known, including eggs similar to indeterminate theropods, dromaeosaurs, caenagnathids and enantiornithes. This ecosystem was humid.

## References

1. ↑ https://twitter.com/DavidEvans\_ROM/status/1498720924287356933
2. ↑ https://en.wikipedia.org/wiki/Willow\_Creek\_Formation
3. ↑ https://www.researchgate.net/publication/270582382\_Evidence\_of\_a\_giant\_tyrannosaurid\_Dinosauria\_Theropoda\_from\_the\_Upper\_Cretaceous\_Campanian\_of\_Montana
4. ↑ https://pbs.twimg.com/media/FBgWN6ZXsBEwZ9W?format=jpg&name=large
5. ↑ https://twitter.com/TM9380/status/1447918440510115850
6. ↑ https://www.tandfonline.com/doi/abs/10.1080/08912963.2013.807252?journalCode=ghbi20
Copedelphys

*Copedelphys* is an extinct genus of marsupial that lived in North Dakota during the Oligocene.

## Description

—Paleontologist Clint Boyd
*Copedelphys* is differentiated by five other specimens found in the same region by their teeth possessing an extra tooth cusp. *Copedelphys* helps paleontologists pinpoint the evolutionary lineage of small mammals in North Dakota, and how they eventually all go down the same path; evolving into one species.

## References

https://www.inforum.com/news/science-and-nature/6573306-Paleontologists-discover-new-species-of-marsupial-in-Brule-Formation
Compsosuchus

*Compsosuchus* is a dubious genus of noasaurid that lived in India during the Late Cretaceous.

## Description

The holotype has morphology very similar to *Masiakasaurus* and is about twice as large. Like it, the pneumatic foramen are large, rounded and adjacent to the parapophysis. However, it differs through the atlantal intercentrum, which is slightly more upturned and (proportionally) less projected odontoid. Carrano et al. (2011) find that the Indian theropod fauna it is a part of seems to be taxonomically oversaturated.

## Classification

Though often considered an abelisaurid, *Compsosuchus* is often thought to have been an abelisaurid dinosaur closely related to *Carnotaurus* and *Indosaurus*. However, *Compsosuchus* is now considered a nomen dubium in Noasauridae

## Notable Specimens

* GSI K27/578: An axis and an articulated axial intersection described in 1933 by von Huene and Matley.

## References

* https://en.wikipedia.org/wiki/Compsosuchus
* https://repository.si.edu/bitstream/handle/10088/11721/SCP95\_Carrano\_web-FINAL.pdf?sequence=1&isAllowed=y