recursal/Fanatic-Fandom huggingface dataset:
Pliosaurus

Credit: Mario Lanzas.

*Pliosaurus* is an extinct genus of pliosaur that lived in South America and Europe during the Late Jurassic.

## Description

*Pliosaurus* is known from many specimens, most of which are semi-complete. Pliosaurus bears a massive head, filled with pointing cylindrical teeth. Compared to other pliosaurs, *Pliosaurus* has proportionally larger flippers. Each tooth was about 30 centimeters (12 inches) long. Species vary in size, thee largest being *P. funkei* and the smallest *P. macromerus*. *Pliosaurus* cruised the open oceans, raising its front two flippers while the back two were angled down (and vice versa). *Pliosaurus* used its back flippers especially when in pursuit of prey, flipper bone studies suggest. *P. funkei*'s brain is similar in size and proportion wise to a great white shark. 13 traditional species have been named, with 1 attached to an uncertain genus, 1 that is disputed to be different from others, 1 set of remains thought to belong to *P. kevani* and an additional 2 unnamed. Several remains of Thalassophonea indet. and Pliosauridae indet. have been attributed to *Pliosaurus*, although many re-descriptions will have to be published and more research will have to be done.

## Species

* *P. almanzaensis*
* *P. brachydeirus*
* *P. brachyspondylus*
* *P. carpenteri*
* *P. funkei* ("Predator X")
* *P. macromerus*
* *P. patagonicus*
* *P. portentificus*
* *P. rossicus*
* *P. westburyensis*
* *P. irgisensis*
* *P. chilensis*
* *P. kevani*
* *"P." andrewsi*
* *P. ?rossicus*

## Synonyms

### Genus Synonymy

* *Stretosaurus*
* *Spondylosaurus*

### Species Synonymy

* *Plesiosaurus giganteus*
* *Plesiosaurus recentior*
* *Liopleurodon rossicus*

## References

* https://en.wikipedia.org/wiki/Pliosaurus
* https://en.wikipedia.org/wiki/Kimmeridge\_Clay#Plesiosaurs
Psephodus

*Psephodus* is an extinct genus of fish that lived in North America, Europe and Asia during the Carboniferous.

## Description

*Psephodus* is only known from fossil teeth, which are rhomboidal in shape. Their teeth bear four or five cornered and slightly convex, strongly arched crowns with a finely punctate surface and crenulated borders. The size and shape of their teeth often vary greatly.

## Species

* *P. crenulatus*
* *P. depressus*
* *P. dubius*
* *P. indicus*
* *P. latus*
* *P. levissimus*
* *P. lunulatus*
* *P. magnus*
* *P. obliquus*
* *P. placenta*
* *P. politus*
* *P. regularis*
* *P. reticulatus*
* *P. salopiensis*
* *P. symmetricus*

## References

1. ↑ https://www.wordnik.com/words/psephodus
2. ↑ https://twitter.com/palaeokatie/status/1319713903941738497
3. ↑ https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=34782
Primaevifilum

P. septatum. Credit: NASA.

*Primaevifilum* is an extinct genus of basal prokaryote that lived in Australia during the Early Archean.

## Description

—J. William Schopf
*Primaevifilum amoenum* was between 60–90 micrometers in length. It is vermiform in overall shape, with a body consisting of roughly 50 segments. *Primaevifilum's* discovery showed life on earth started long before previously imagined, which indicates it may have been easier than assumed. *Primaevifilum* was discovered in 1992, and appears as small squiggle patterns in ~3.4-billion-year-old rocks. J. William Schopf and team used secondary ion mass spectroscopy to analyze the carbon signature in the fossils. They found three microorganisms, at least, and they were definitely not mineral deposits, though they would have had near-identical signatures. *P. minutum* produced carbon upon light intake. *P. amoenum* consumed methane and *P. delicatulum* fits into Archaea. However, evidence of sulfur-consuming organisms also exists. This places 3.465 billion years as a time where life was already diversified, but the true origin is difficult to estimate. The discovery of *Primaevifilum* states life is relatively easy to produce, where Schopf et al. hypothesize about the presence of extraterrestrial life.

*Primaevifilum* is known from the Apex Chert, being the oldest fossils, and first described in 1933.

## Species

* *P. amoenum*
* *P. attenuatum*
* *P. delicatulum*
* *P. laticellulosum*
* *P. minutum*
* *P. septatum*

## Gallery

*P. amoenum*.*P. delicatulum*.*P. minutum*.
## References

1. ↑ J. W. Schopf. 1993. Microfossils of the Early Archean Apex Chert: New Evidence of the Antiquity of Life. *Science* **260**: 640-646
2. ↑ https://www.businessinsider.com/earth-oldest-fossils-show-life-evolved-more-than-3-5-billion-years-ago-2017-12
3. ↑ https://www.eurekalert.org/multimedia/pub/158620.php?from=380017
Protemnocyon

*Protemnocyon* is a yet unclassified genus of canid that lived during the Early Oligocene in North America.

## Description

Not much is known about *Protemnocyon*, only that it lived in Nebraska (Hat Creek Basin) from 33.9 to 33.3 million years ago. The type, No. 552, is a skull and mandible found by a Mr. Peterson and first proposed to be a new genus related to *Temnocyon*. The genus is differentiated from a short crest with low sagittal crests and robust premolars. Jean Ringier Hough (1948) redescribed *Protemocyon* and allied genera from additional remains, finding similar conclusions; additional specimens include USNM 17844 and USNM 18845. The tope of the skull is flat in the lateral. *Temnocyon* sits closer to *Canis* than *Protemnocyon* does based on time and by the auditory bullae. It is differentiated through a very low sagittal crest on the anterior 2/3 of the skull. an inflated endocast (suggesting a brain .5x proportionally larger than *Daphoenus*), a unique dental formula and an imperfectly-keeled inferior M2. The specific epithet *inflatus* is in relation to an inflated endocast.

## Notable Specimens

* CM 552: The type specimen of *Protemnocyon*.

## References

* https://en.wikipedia.org/wiki/Protemnocyon
* https://www.science.org/doi/pdf/10.1126/science.17.440.912
* https://www.jstor.org/stable/1299593
* https://www.journals.uchicago.edu/doi/pdf/10.1086/278320
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=41279
* https://archive.org/details/oligocenecanidae12hatc
Saraikisaurus

"Saraikisaurus" is a naked genus of pterodactyloid pterosaur that lived in Pakistan during the Late Cretaceous.

## Description

"Saraikisaurus" is known exclusively from a dentary ramus, though there are some referred specimens. Its dentary possessed partially overlapping teeth, indicating that, should its pterosaurian affinities be confirmed, it would be the only toothed pterosaur from the end of the Cretaceous.

## References

* Malkani, M. Sadiq. (2021). Formal description of poripuchian titanosaurs, theropods, mesoeucrocodiles, pterosaur, snake and bird from the latest Maastrichtian Vitakri Formation of Pakistan. Open Journal of Geology. 11. 275-318.
Sabertooth salmon

## Oncorhynchus rastrosus

Credit: Lucas Lima.

The sabertooth salmon (*Oncorhynchus rastrosus*) is an extinct species of salmon that lived offshore in North America from the Late Miocene to the Early Pliocene.

## Description

The fish first appeared in the Late Miocene of California, off the coast of North America. Adults were 2.7 meters (9 feet) long, and migrated seasonally like modern salmon. Being the largest species in *Oncorhynchus*, this fish had a pair of fangs that erupted from the snout's tip. This feature describes the names of both the species epithet and synonym. Additionally, adults had larger gill rakers than modern relatives, meaning adults were likely planktivorous. Two fossils were discovered from Oregon, are 5 million years old and show articulated teeth. Kerin Claeson, of the Philadelphia College of Osteopathic Medicine, states the fish likely had no other teeth, and acknowledges that they may have had more than modern salmon, reabsorbing them during breeding season. They faced outwards, likely as weapons or to move rocks on the marine beds to secure eggs.

## References

* http://www.eartharchives.org/articles/saber-toothed-salmon-teeth-more-like-tusks-than-fangs/
* https://en.wikipedia.org/wiki/Oncorhynchus\_rastrosus
Sphenodon diversum

*Sphenodon diversum* is an extinct species of reptile that lived in North Island, New Zealand, presumably from the Miocene.

## History

Near the end of November, 1885, William Colenso had received a small package containing bones from a Mr. Mills. It was from the nearby wood and coal depot, where miners found the remains in the morning, ~45 below the surface. Colenso, who was suffering of a sickness at the time, briefly examine the remains, identifying them as a small reptile. Though they were well preserved, including small details, they were not fossilized and very few of the skeleton remained. The quarry, which he supposed was far, was found to be close. When send to recover more material, the man returned with three new bones, two of them pelvises. He examined them all the next day, assigning it to *Sphenodon* but not a species. Of these materials, he erected *S. diversum* to house the remains. More remains may have been in possession by a Dr. Newman.

## References

* https://en.wikipedia.org/wiki/Tuatara
* https://paperspast.natlib.govt.nz/periodicals/TPRSNZ1885-18.2.5.1.23
* https://www.jstor.org/stable/4523786
Smok

Credit: The K-Tumblr Boundary.

*Smok* is an extinct genus of large carnivorous archosaur that lived in Poland during the Late Triassic period.

## History

It was discovered near Lisowice village in the Latest Norian-Early Rhaetian-aged rocks. Ever since, this area has been recognized to provide fossils. ZPAL V.33/15 (a partial braincase and postcrania) is the holotype and was named in 2008.

## Description

*Smok* was one of the largest carnivorous archosaurs in central Europe at this time. The skull is 50-60 centimeters long. THe serrated teeth and the contacted jugal and quadratojugals indicate it was an archosaur.

## Paleoecology

*Smok* was the largest predator in it's environment and was contemporaneous with *Liliensternus*, *Polonosuchus* and *Teratosaurus*. Larger archosaurs would not appear until the Jurassic. It was also contemporaneous with small dinosauromorphs, poposauroids and dicynodonts. Martin Qvarnström et al. examined referred coprolites to fine crushed bone that was crushed by the animal itself and the ability to retain food inside it's gut with varied considerability based on their availability and type. The mix of bones (some of which were fish, dicynodonts and temnospondyls) demonstrate it was a generalist.

## References

* https://app.pan.pl/archive/published/app57/app20100045.pdf
* https://www.app.pan.pl/archive/published/app53/APP53-733.pdf
* https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6353991/
* https://www.smithsonianmag.com/science-nature/the-dinosaur-that-wasnt-61179197/
* https://www.researchgate.net/publication/329315001\_A\_new\_occurrence\_of\_the\_Late\_Triassic\_archosaur\_Smok\_in\_southern\_Poland
* https://www.researchgate.net/figure/A-predatory-archosaur-Smok-wawelski-gen-et-sp-nov-Lisowice-Lipie-Slaskie-clay-pit\_fig2\_237296171
* https://pterosaurheresies.wordpress.com/2011/09/11/what-is-smok/
* https://www.eurekalert.org/news-releases/838032
Suskityrannus

Credit: Andrey Atuchin.

*Suskityrannus* is an extinct genus of tyrannosaur that lived in North America during the Late Cretaceous.

## History

Before *Suskityrannus*' format naming, the TV documentary, Planet Dinosaur dubbed the genus as 'Zunityrannus'. This name derives from the nicknames dubbed by researchers; 'Zuni coelurosaur/tyrannosaur'.

## Description

*Suskityrannus* is a small-bodied tyrannosaur that is about 3 meters long, 1 meter tall, and around 20-40 kilograms in weight. *Suskityrannus* is around the size of a coyote, hence the name 'coyote tyrant'. *Suskityrannus* is less stocky than larger-bodied tyrannosaurs, and has three finger unlike later descendants. *Suskityrannus* has considerably longer limbs, and a long tail.

## Notable Specimens

* MSM P4754 "The Smiling Face", "Littletooth": A partially articulated skull and postcranial bones, and is the holotype fossil of *Suskityrannus*.
* MSM P6178: The paratype specimen consisting of a partially articulated skull bones and an incomplete postcranial skeleton.

## References

* https://en.wikipedia.org/wiki/Suskityrannus
* https://blogs.scientificamerican.com/laelaps/tiny-tyrannosaur-named-the-coyote-king/
Semirostrum

Credit: Robert Boessenecker.

*Semirostrum* is an extinct genus of porpoise that lived in California during the Pliocene.

## Description

*Semirostrum* is characterized by its lower jaw, which is twice the length of the upper jaw. *Semirostrum*'s mandible symphasis is 85 centimeters long, were a porpoises is 1-2 centimeters long.

## Paleoecology

*Semirostrum* would have probed through loose sediment on the shorelines and estuaries in California during the Pliocene. *Semirostrum* would have used its jaws to scoop small animals into its teeth-lined jaws.

## References

https://en.wikipedia.org/wiki/Semirostrum
Siksika

Credit: YellowPanda2001 on the Wikipedia Commons.

*Siksika* is an extinct genus of petalodontid chondrichthyan fish that lived in Montana during the Early Carboniferous.

## History

It is named after the Siksika Nation, with "Siksika" itself translating to "Blackfoot". It was named by Lund (1989) after the specimen MV 6199, a braincase, mandibles, eye pigments and teeth. The genus is often reported from teeth. These all suggest having a relationship with *Janassa* and *Netsepoye*.

## Paleoecology

The holotype was discovered from MV 7106, Supercrop Quarry, Bear Gulch, which is a part of the Heath Formation and was once a Arnsbergian lagoonal/restricted shallow subtidal area. Today, it is a limestone formation in Montana.

## References

* https://en.wikipedia.org/wiki/Siksika\_ottae
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=151678
Rhynchosaurus

*Rhynchosaurus* is an extinct genus of rhynchosaurs that lived in Europe during the Middle Triassic.

## Description

Two additional species of *Rhynchosaurus* were named: *R. spenceri* and *R. brodiei*, being reassigned to *Fodonyx* and *Langeeronyx*, respectively. *Rhynchosaurus* was small and quadrupedal, having a flat-shaped head and a large beak.

## References

https://en.wikipedia.org/wiki/Rhynchosaurus
Presbyornis

Credit: Vitor Silva.

*Presbyornis* is an extinct genus of presbyornithid anserimorph bird that lived in the Maryland, Utah, Mongolia, England?, Colorado and Wyoming from the Paleocene (possibly starting in the Mesozoic) to the Eocene.

## History

*P. pervetus* is known from many complete skeletons from the Green River Formation, which suggests that they nested in colonies and may have been susceptible to botulism lile many shorebirds are today. *P. isoni* is known from the Aquia Formation from humerus USM 294116 and finger phalanx USNM 294117. Humeri assigned to *Headonornis* (BMNH PAL 3686, 5105 and 6240) are sometimes assigned to this genus but their age may suggest a new taxon. *P. recurvirostris* is disputed and possibly synonymous with *P. pervetus*. It was named from the partial wing KUVP 10105 from the Colton Formation of the Wasatch Plateau. Undescribed fossils from the Paleocene of Utah and the possible Early Oligocene of Mongolia are known. One coracoid assigned to *Headonornis* may actually represent a *Presbyornis*.

## Description

It was initially mistaken for a flamingo due to the long neck and legs but was reclassified as an anserimorph when the duck-like skull were discovered. *Presbyornis* was once posulated to represent a transition from anserimorphs to shorebirds but is reclassified as closer to modern screamers.

## Paleobiology

*Presbyornis* likely waded in shallow lakes and ate similarly to a flamingo/dabbling duck by using the flat bill to filter small plants and animals. *Presbyornis* lived in North America and Eurasia. This genus may have first appeared during the Mesozoic. It is presumed to have lived in small colonies around shallow lakes.

## Reference

* Dorling Kindersley Encyclopedia of Dinosaurs and Prehistoric Life, p. 145
* https://en.wikipedia.org/wiki/Presbyornis
Pseudorhaptagnostus

Credit: Revision of Pseudorhaptagnostus Lermontova (?Trilobita, Agnostida).

*Pseudorhaptagnostus* is a dubious extinct genus of trilobite that lived in Asia during the Cambrian.

## Description

   The genus *Neoagnostus* and *Machairagnostus* are argued junior synonyms of *Pseudorhaptagnostus* in a scientific paper released in 2016. It was later synonymized with *Neoagnostus*.

## References

* https://www.researchgate.net/publication/295090353\_Revision\_of\_Pseudorhaptagnostus\_Lermontova\_Trilobita\_Agnostida
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=19276
Polacanthus

Credit: A Dinosaur A Day.

*Polacanthus* was a genus of ankylosaurid which lived during the Early Cretaceous in what is now southern England.

## Description

Compared with many other British dinosaurs, it is relatively well represented in fossils, however only the rear end of the animal is fully known and the front of the animal has often been poorly preserved. Most reconstructions therefore use closely related genera such as *Gastonia* as references. *Polacanthus* had a large bony 'shield' made of osteoderms over its pelvis and four rows of spikes running along abdomen and neck. Its armour would have provided protection against large and medium predators such as *Neovenator* and *Eotyrannus*.

## Discovery and naming

The holotype *Polacanthus* was found in 1865 by clergyman and palaeontologist William Fox on the Isle of Wight. It was named by Richard Owen later that year, its species name honouring its founder. Since then numerous other specimens have been found.

In 1928 a new genus of ankylosaurian was named *Polacanthoides*. However this was later found to have been a mixture of *Polacanthus* and *Hylaeosaurus* fossils.

In 1996 a reportedly new species of *Polacanthus* was found and named *P. rudgwickensis*. This species was much larger than *P. foxii*, but later fossils showed this was a completely new genus. It was named *Horshamosaurus* in 2015. In the late 1980s and early 1990s, it was also suggested the genus *Hoplitosaurus* from the Lakota Formation was a North American species of *Polacanthus*, but this was later disproved.

## References

* https://en.wikipedia.org/wiki/Polacanthus
* http://www.prehistoric-wildlife.com/species/p/polacanthus.html
Sigilmassasaurus

Credit: Connor Ashbridge on the Wikimedia Commons.

When the genus was initially described, the validity of the genus was immediately challenged shortly after the papers' release. The initial response notes that *Carcharodontosaurus* was synonymous with Sigilmassasaurus. After a paper was released in 2014, the genus was challenged once more. The study stated that *Spinosaurus aegyptiacus* was synonymous with *Sigilmassasaurus*, and *Spinosaurus maroccanus* was considered dubious.

The current scientific consensus is that *Sigilmassasaurus* is valid, but has yet to be disproved. However, in 2021, a new research suggests that the spinosaurid is indeed a distinct species from *Spinosaurus*; based on a fossil specimen that shows a high degree of differentiation.

The recent research cited a unique, highly differentiated fossil. It is described as a highly unusual mid-cervical vertebra belonging to a large spinosaurid from the Cenomanian Kem Kem Group of Morocco is described. It is compared to the characteristic morphology of each reconstructed cervical position in *Spinosaurus aegyptiacus*, based on a recent composite reconstruction that incorporates most previously referred material from this unit. Rather than conforming to any of the previously identified cervical positions in its morphology, the specimen displays a unique combination of mid-cervical characters, with the relatively compact centrum.

Furthermore, it displays two characters that are previously unknown in spinosaurid mid-cervicals from the Kem Kem Group: a rounded hypapophyseal tuberosity that is not continuous with a ventral keel, and a moderately developed, dorsally oriented epipophysis that does not overhang the postzygapophysis posteriorly. The diagnostic value of positionally variable cervical vertebral characters in spinosaurid systematics is discussed. Although limited, the new data could lend support to the controversial hypothesis that two spinosaurid taxa are represented in the Kem Kem Group. A current cladogram:

## Notable Specimens

* FCDR05-8: *Spinosaurus maroccanus* teeth from the Kem Kem. FCDR05 is 45 millimeters long, FCDR06 is 37 millimeters long, FCDR07 is 37 millimeters long and FCDR08 is 39 millimeters long.

## Gallery

Kem Kem slender-spined spinosaurid indet.
**Credit: Olof Moleman.**Kem Kem slender-spined spinosaurid indet.
**Credit: Olof Moleman.**FCDR05.FCDR06.FCDR07.FCDR08.
## References

* https://www.researchgate.net/publication/258761392\_A\_reevaluation\_of\_Sigilmassasaurus\_brevicollis\_Dinosauria\_from\_the\_Cretaceous\_of\_Morocco
* https://journals.library.ualberta.ca/vamp/index.php/VAMP/article/view/29370
* https://cdnsciencepub.com/doi/10.1139/cjes-2012-0129
* http://www.educationalfossils.com/edfossils/fossil-collections-dinosaur.htm
Rubeosaurus

Rubeosaurus with nasal horn based on remains now attributed to Stellasaurus. Credit: Cisiopurple on DeviantArt.

## Statistics

### Diet

Herbivorous

*Rubeosaurus* is a possibly dubious genus of centrosaur that lived in North America during the Late Cretaceous.

## Description

The holotype of *Rubeosaurus*, USMN 11869 consists of a parietal, and a second specimen, MOR 492 a partial skull with a mandible, partial left premaxilla, co-ossified nasal and horncore, left postorbital and horncore and a nearly complete right parietal. The remains were formerly attributed to *Styracosaurus*, but named *Rubeosaurus* in 2010. It is known for its broad-based nasal horn and frill ornamentation. Each edge has only two of straight horns, and two pars that point towards the midline and converge. Immature specimens may exist, under the genus *Brachyceratops*. In 2007, Michael J. Ryan et al. argued that *Brachyceratops* may be an immature *Rubeosaurus*. A 2011 study showed that the most mature specimen, USNM 14765, shows a single apomorphy common with *Rubeosaurus* than any other centrosaur. The same study suggests that USNM 14765 is too immature and too incomplete to preserve any apomorphies. However, *Brachyceratops* can not be considered a senior synonym of *Rubeosaurus*.

Holmes et al. in the press argued that diagnostic characters in *Rubeosaurus* fall in the range of specific anatomical variation known in *Styracosaurus*. They considered *Rubeosaurus* a junior synonym of *Styracosaurus*.

## References

* https://en.wikipedia.org/wiki/Rubeosaurus (link discontinued)
* New Material of "Styracosaurus" ovatus from the Two Medicine Formation of Montana, Andrew T. McDonald and John R. Horner, pages 156-168
* On dinosaurian reptiles from the Two Medicine Formation of Montana, Charles Gilmore, pages 1-39
* https://www.biodiversitylibrary.org/page/32382634
* http://www.bio.ucalgary.ca/contact/faculty/pdf/russell/314.pdf
* https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3154267
* https://www.cambridge.org/core/journals/journal-of-paleontology/article/abs/new-material-and-systematic-reevaluation-of-medusaceratops-lokii-dinosauria-ceratopsidae-from-the-judith-river-formation-campanian-montana/852C434AB7EC109D5654742EAB15FDEC
* https://www.sciencedirect.com/science/article/abs/pii/S0195667119301946?via%3Dihub
* https://archive.org/details/g.s.paul2016theprincetonfieldguidetodinosaurs/page/n253/mode/1up
Syllipsimopodi

*Syllipsimopodi* is an extinct genus of vampyropod cephalopod that lived in Montana during the Early Cretaceous.

## History

B. Hawes donated the type specimen, ROMIP 64897, to the Royal Ontario Museum in 1988. In 2022, over 30 years later, Whalen and Landman named it. The name derives from Greek, meaning "prehensile foot" (after the evolution of suckers to grasp objects) and the specific epithet is after Joe Biden, 46th president of the United States.

## Description

It is known from the Bear Gulch Lagerstätte, represented by a specimen with a gladius and 10 robust arms, with what appears to be some of the oldest preserved suckers. This would make it the oldest vampyropod with ancestral ten arms, which pushes back their origin to ~81.9 million years. This challenges the common theory that vampyropods descend from Triassic phragmoteuthid belemnoids. *Syllipsimopodi* lacks a chambered phragomocone and an archaic rostrum, which are retained in belemnoids and decabrachians. A pair of arms may have been elongate, and with a long gladius and terminal fins, suggests a convergent squid-like bauplan in the earliest vampyropods. The gladius is simple and nearly triangular, with a funnel-like conus and a median field and median rib. No hyperbolar zones, cone flags or lateral reinforcements are found, with lateral fields to be unlikely. The biserial sucker rows bear no hooks or cirri, with the elongate arms possibly being taphonomic in origin. There is an inc sac and a single fin pair.

## Paleoecology

*Syllipsimopodi* died in a low-latitude shallow marine back with oscillating semi-arid and tropical conditions, which aided in preservation alongside microturbites that were deposited by seasonal monsoons. Monsoon rainfall would have rapidly introduced terrestrial sediments and biomatter into this bat, which would have fed algal blooms and created short-lived anoxic sones with saline instability via rapid injection of voluminous freshwater. Bear Gulch is possibly the best known pelagic fauna of the central basin and bay mouth, with chondrichthyans, coelacanthiforms, malacostracans, polychaetes and cephalopods; the first two were especially diverse. This locality preserves organisms in such great detail that small details can often be seen.. Benthic fossils are rare here, with marginal facies providing gastropod, worm, asterozoan and many sponge fossils, who were substrate for brachiopods, bivalves and conulariids. However, crinoids, bryozoans and corals are nearly absent, with algae (especially dasyclads) being common all-around.

## References

* https://www.nature.com/articles/s41467-022-28333-5
* https://t.co/PzkP5cnwDF
* http://www.sci-news.com/paleontology/syllipsimopodi-bideni-10605.html
Platyscaphokogia

Credit: Jaime Bran.

*Platyscaphokogia* is an extinct genus of dwarf/pygmy sperm whale that lived in Peru during the Late Miocene.

## Description

*Platyscaphokogia* is known from two skull specimens, which have a number of aspects similar and distinct from related genera. *Platyscaphokogia* has a spoon-like neurocranium, a non-pachyostotic snout, which is thin from the dorsoventral angle and points towards the anterior angle.

## Classification

*Platyscaphokogia* is a sister taxon with *Scaphokogia*, and shares Scaphokoniinae. Researches regard *Platyscaphokogia* as an early stage of Scaphokoniinae, based on its cranial anatomy.

## Paleoecology

*Platyscaphokogia* was likely raptorial, built for a predatory life alongside the water column of relatively open environments.

## References

* Collareta, Alberto, et al. “A New Physeteroid from the Late Miocene of Peru Expands the Diversity of Extinct Dwarf and Pygmy Sperm Whales (Cetacea: Odontoceti: Kogiidae).” *SciencePress*, 5 Oct. 2020, sciencepress.mnhn.fr/sites/default/files/articles/pdf/comptes-rendus-palevol2020v19a5.pdf.
Seirocrinus

Credit: Franz Anthony.

*Seirocrinus* is an extinct genus of crinoid that lived during the Jurassic.

## Description

*Seirocrinus* grew taller than the average human, and had flowery 'leaves' on the end of its 'stem'. Though *Seirocrinus* appears to be a plant at a glance, it is rather an advanced crinoid, ancestral to sea stars, sea urchins, brittle stars and sea cucumbers.

## Paleoecology

*Seirocrinus* lived in large colonies that attached upside down to driftwood and debris. *Seirocrinus* is planktivorous, using its 'leaves' to catch small prey.

## References

Studio 252 on Tumblr

https://dinopedia.fandom.com/wiki/Seirocrinus
Succinodon

A-F) supposed sauropod jaw and teeth, G) a life reconstruction of a Kuphus at the bottom of it's tube.

## Statistics

### Diet

Chemoautotrophic or Xylophagous

*Succinodon* is a dubious genus of bivalves that lived in Poland during the Late Cretaceous.

## History

During World War II, German geologist Putzer discovered fragments of wood that had been burrowed into by shipworms, a type of bivalve, in Upper Cretaceous rocks near Warsaw, Poland. In 1941, Friedrich von Huene studied the fossil and described it as the new species *Succinodon putzeri*. Von Heune believed the fossil to be a jaw with teeth of a titanosaurid sauropod dinosaur.

In 1981, Polish paleontologists Krystyna Pożaryska and Halina Pugaczewska reevaluated *Succinodon* and found that it was not in fact a dinosaur, but a piece of wood that had been bored into by bivalve mollucs of the genus *Kuphus*.

## Paleoecology

Like modern shipworms (Teredinidae), *Succinodon* burrowed into wood submerged in fresh water. While most modern shipworms feed on the wood (xylophagy), the one extant species of *Kuphus* has endosymbiotic bacteria that allow it to produce its own food from chemicals in the environment (chemoautotrophy).

## References

1. ↑ https://www.app.pan.pl/archive/published/app26/app26-027.pdf
2. ↑ 2.0 2.1 2.2 2.3 https://www.app.pan.pl/article/item/app26-027.html
3. ↑ https://en.wikipedia.org/wiki/Shipworm
4. ↑ https://en.wikipedia.org/wiki/Kuphus\_polythalamius
Proceratosaurus

Credit: Gabriel Ugueto.

*Proceratosaurus* is an extinct genus of tyrannosaurid theropod dinosaur that lived in England during the Middle Jurassic.

## History

*Proceratosaurus* was found in excavations prior to 1910, for a reservoir near Minchinhampton, Cotswolds, Gloucestershire, England. The upper portion of the skull had been missing because a fissure formed, which eroded rock and filled parts of it with calcite. They prepared the left side, and donated the find to the Natural History Museum by F. Lewis Bradely F.G.S.. Arthur Smith Woodward published it in 1910.

## Classification

Woodward placed *Proceratosaurus* as a species of *Megalosaurus* because they both shared 4 premaxillary teeth. Friedrich von Huene (1930s) suggested it was closer to *Ceratosaurus*, and Huene thought both were coelurosaurians. Until the late 1980s came, and *Ceratosaurus* was found to be a primitive theropod and not a coelurosaur, and Proceratosaurus was reexamined Gregory S. Paul thought it was close to *Ornitholestes*, due to the crest on the snout (which was disproven in *Ornitholestes*. He considered both primitive allosauroids, thinking *Piveteausaurus* and *Proceratosaurus* were the same animal (*Proceratosaurus* would take priority, if that were the case. However, no elements between them overlap, with later studies differentiating them.

Phylogenetic studies in the early 2000s placed both *Proceratosaurus* and *Ornitholestes* as coelurosaurs, distantly affiliated with ceratosaurs and allosaurs. However, the opinion *Proceratosaurus* was a ceratosaurid was published in 2000, but was presented without evidence. Thomas R. Holtz Jr. (2004) performed phylogenetic analysis, placing *Proceratosaurus* into Coelurosauria, and found it was related to *Ornitholestes*, but this was weakly supported. Oliver Rauhut et al. (2010) published the first major reevaluation, concluding it was a coleurosaur, and further, a tyrannosauroid. They found it was close to *Guanlong*, forming a clade which they coined "Proceratosauridae". This was defined by all theropods closer to *Proceratosaurus* than to *Tyrannosaurus*, *Allosaurus*, *Compsognathus*, *Coelurus*, *Ornithomimus* and *Deinonychus*.

## References

https://en.wikipedia.org/wiki/Proceratosaurus
SS Mount Temple hadrosaur

The SS Mount Template hadrosaur is an indeterminate genus of hadrosaur that lived in Alberta during the Late Cretaceous.

## Description

It was part of the cargo hold of the SS Mount Temple, a ship that sunk in the Atlantic in 1916 after a German submarine attacked her. The manifest were "hundreds" or "thousands" of unidentified fossils, 4 articulate hadrosaurs (one cf. *P. walkeri*, 2 *Corythosaurus*? or *Prosaurolophus* and a new species), a partial *Champsosaurus* skeleton (presumed; Sternberg's letters makes a typo), a *Judithemys*-like turtle (possibly a new species), a *Boremys* carapace, a *Trionyx latus* carapace and a fairly complete *Chasmosaurus* skull. All of these fossils were kept in the cargo hold and lost during the sinking. It is one of four articulated/associated hadrosaurs in the cargo hold. An unidentified hadrosaur skull was also on board.

## References

* https://www.youtube.com/watch?v=mS7iq7LJ1MA&ab\_channel=RoyalTyrrellMuseumofPalaeontology
* https://en.wikipedia.org/wiki/SS\_Mount\_Temple#Sinking
Sinornithosaurus

Credit: FunkMonk on the Wikimedia Commons.

*Sinornithosaurus* is an extinct genus of microraptorian dromaeosaurs that lived in China during the Early Cretaceous.

## Description

*Sinornithosaurus* was a small four-winged dromaeosaurid, closely related to *Microraptor*. It possessed advanced feathers on its wings and body, though they were not as advanced as those of modern birds. For this reason, it has been hypothesized that it was capable of gliding but not powered flight.  In 2010, G.S. Paul synonymized many dromaeosaurid species into *Sinornithosaurus*, which is not supported.

## Species

### Reassigned Species

* *"S." lujiatunensis*
* *"S." ashile*
* *"S." zhaoianus*
* *"S." yangi*

## Notable Specimens

* IVPP V12811 - holotype, partial skeleton including most of the skull
* NGMC 91, nicknamed "Dave", nearly complete skeleton and skull with impressions of feathers showing four wings. Likely represents a juvenile individual, but also suggested to represent a second unnamed species.

## References

1. ↑ 1.0 1.1 https://en.wikipedia.org/wiki/Sinornithosaurus
2. ↑ https://archive.org/details/g.s.paul2016theprincetonfieldguidetodinosaurs/page/n87/mode/2up
3. ↑ https://commons.wikimedia.org/wiki/File:Sinornithosaurus\_millenii.jpg
Stegouros

*Stegouros* is an extinct genus genus of Ankylosaurian dinosaur that lived in South Chile during the Late Cretaceous.

## History

The genus name means "roofed tail" and the specific epithet "of elenagassen", a mythological armoured monster of the Aónik’enk. The genus was first found in a 2021 preprint. It gained popularity and, however, the authors stated invalidly publishing the name in preprint was a bad idea. In December 2021, the genus and species were formally named.

## Description

*Stegouros elengassen* consists of one mostly complete, semi-articulated adult specimen, CPAP-3165. The taxon is very typical of Ankylosauria with the exception of its slender limbs, and most parts of the skull, which look more like that of any Eurypodan. The tail of *Stegouros* is very unique, it is a series of flat osteoderms that is unlike those found in any Thyreophoran to date, although related taxa in it's clade do not have tails preserved, so it is likely that other taxa had similar caudal weaponry. It dates from the Campanian to the Maastrichtian.

## Classification

The taxon was grouped in a clade with the Australian taxon *Kunbarrasaurus* and the Antarctic taxon *Antarctopelta* called Parankylosauria (The first ancestor of *Stegouros* but not *Ankylosaurus*, and all descendants) of. A similar clade proposed by Gregory S. Paul (2010), being the same as the proposed clade, but also includes *Minmi*; he calls this clade Minmidae. This clade, however, was not properly stated, making it invalid. Nonetheless, the following was found:

## References

* https://www.researchgate.net/publication/355921850\_Bizarre\_tail\_weaponry\_in\_a\_transitional\_ankylosaur\_from\_subantarctic\_Chile
* Paul, Gregory S. The Princeton Field Guide to Dinosaurs. Princeton University Press p. 227 ISBN 978-0691137209
* https://www.nature.com/articles/s41586-021-04147-1
* https://www.smithsonianmag.com/smart-news/new-species-of-ankylosaur-unearthed-in-chile-had-a-flat-weapon-like-tail-180979159/
* http://www.sci-news.com/paleontology/stegouros-elengassen-10348.html
* https://phys.org/news/2021-12-dinosaur-tail-chile-stuns-scientists.html
Protiguanodon

Holotype AMNH 6253. Credit: Skye McDavid.

*Protiguanodon* is a dubious genus of ceratopsian that lived in ongolia during the Early Cretaceous.

## Description

*Protiguanodon* was described as distinct by Osborn (1923) from *Psittacosaurus mongoliensis* based on features from the crania. However, many consider these features to be insignificant and lump it into the former. The specimen is not identical to *Psittacosaurus mongoliensis*, and was as such later renamed *Psittacosaurus protiguanodonensis* by C.C. Young (1958). The specimen was first thought to be an iguanodont, named as the only genus in "Protiguanodontinae (which was a part of Iguanodontidae), but later grouped with psittacosaurs in Ceratopsia. Osborn himself was unsure if *Protiguanodon* and *Psittacosaurus* were different animals, ending his 1923 paper stating that the former will take precedence over *Protiguanodon*. AMNH 6523 was assigned the type, being 1.35 meters long with a forelimb 12 inches, a hindlimb 480 millimeters, a tail 710 millimeters long and thoracic vertebrae 340 millimeters long. 11 gastroliths are present. Teeth 4 and 6 are less worn, 3 and 8 are advanced in wear and 1 and 7 are fully worn. The type is immature. Supposedly, it was differentiated by: no dental armature, comparatively unlike crania and postcrania and wide geologic separation. Osborn states that resolving the identity of the type will require the comparing of *Psittacosaurus mongoliensis*.

## Gallery

AMNH 6253, the type of Protiguanodon, drawn by John Germann as it was in situ.
## References

* https://animals.howstuffworks.com/dinosaurs/psittacosaurus.htm
* https://digitallibrary.amnh.org/bitstream/handle/2246/3267//v2/dspace/ingest/pdfSource/nov/N0095.pdf?sequence=1&isAllowed=y
* https://en.wikipedia.org/wiki/Psittacosaurus
* Young, C. C. (1958). "The dinosaur remains of Laiyang, Shantung". *Palaeontologia Sinica Series C*. **16**: 53–159.
* Sereno, Paul C. (2010). "Taxonomy, cranial morphology, and relationships of parrot-beaked dinosaurs (Ceratopsia:*Psittacosaurus*)". In Ryan, Michael J.; Chinnery-Allgeier, Brenda J.; Eberth, David A. (eds.). *New Perspectives on Horned Dinosaurs: The Royal Tyrrell Museum Ceratopsian Symposium*. Bloomington and Indianapolis: Indiana University Press. pp. 21–58.
* https://books.google.ca/books?vid=ISBN9780520242098&redir\_esc=y
* Osborn, Henry F. (1924). "*Psittacosaurus* and *Protiguanodon*: Two Lower Cretaceous iguanodonts from Mongolia". *American Museum Novitates* (127): 1–16.
Saint Bathans Mammal

Credit: Harpier

The Saint Bathans Mammal is an undescribed genus of mammal that lived from the Early/Late Miocene in New Zealand.

## Discovery and Description

The only fossil evidence of the Saint Bathans Mammal is fragmentary jaw bones and a femur. The Saint Bathans Mammal's fossils are researched, yet no description has yet been released to the public.

## References

https://en.wikipedia.org/wiki/Saint\_Bathans\_mammal
Tachiraptor

Tachiraptor (large)

*Tachiraptor* is an extinct genus of theropod dinosaurs that lived in Venezuela during the Early Jurassic.

## Description

*Tachiraptor* is like a typical theropod, long body, slender, toothy jaws, clawed hands, and long legs. Tachiraptor is at least 1.5 meters long, and was a generalistic predator.

Several differences in anatomy, such as projections on the fibula, and a wide shin, make Tachiraptor differ from other genera.

## Paleoecology

*Tachiraptor* ate smaller dinosaurs and vertebrates in the La Quinta Formation in Venezuela during the Early Jurassic.

## Notable Specimens

* IVIC-P-2687: The holotype of *Tachiraptor*; consisting of one right tibia.
* IVIC-P-2868: Consisting on one left ischium.

## References

https://en.wikipedia.org/wiki/Tachiraptor
Skye Pterosaur

Credit: Martin-Silverstone et al 2022

The Skye Pterosaur is an unnamed genus of pterosaurs that lived on the Isle of Skye during the Middle Jurassic.

## History

The Skye Pterosaur was first described in a preprint uploaded to bioRxiv in February 2022 as "REDACTED gen et sp. nov.", which provides detailed information but does not yet reveal a name. It is to be named by Elizabeth Martin-Silverstone and coauthors; however, the specimen first appears in literature from Martin-Silverstone et al. (2018).

## Description

The Skye Pterosaur is known from proposed holotype NHMUK PV R37110, a partial skeleton preserved in 3 dimensions. It is a darwinopteran, the sister taxon to *Kryptodrakon progenitor*. Several pterosaurian teeth are known from the Kilmaluag Formation as well.

## References

1. ↑ 1.0 1.1 1.2 https://www.biorxiv.org/content/10.1101/2022.02.14.480264v1.full.pdf+html (including preprint draft, as of 2022)
2. ↑ 2.0 2.1 https://discovery.ucl.ac.uk/id/eprint/10108804/
Schizorhiza

Credit: Hyrotrioskjan on DeviantArt.

*Schizorhiza* is a sawfish that lived during the Early/Mid Cretaceous between 83.6 and 66 million years ago in shallow parts of the Tethys Ocean.

## Description

*Schizorhiza* has a long snout barbed with teeth for killing its prey. *Schizorhiza* was often hunted and eaten by its much larger cousin, *Onchopristis*. *Schizorhiza*'s teeth did not fall off when they wore down. New teeth grew below them until the old teeth fell off when their spot was taken by the new tooth. The name 'split roof' refers to the shape of the rostrum and how the teeth grew in.

## Distribution

*Schizorhiza* was a very successful species and ranged all around the globe.

## References

https://en.wikipedia.org/wiki/Schizorhiza
Quercus furuhjelmi

*Quercus furuhjelmi* is an extinct species of tree that lived in Kazakhstan and Alaska during the Paleogene.

## Classification

It is frequently placed in the chestnut or white oak grouping, although the former is most often accepted because some specimens bear sharp teeth like seen in chestnut oaks and probably signifies relation.

## References

https://en.wikipedia.org/wiki/Quercus\_furuhjelmi
Qikiqtania

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

## Statistics

### Diet

Piscivorous

*Qikiqtania* is an extinct genus of elipistostegalian that lived in Nunavut during the Late Devonian.

## History

Neil Shubin, an author of the original publication, teased the genus as a new genus of Stegocephalian thought named "Kikikania", stating that it would "hopefully be described in the next few months". In July 2022, the genus and species were published as *Qikiqtania wakei* by Stewart et al.. The holotype is known from south Ellesmere Island, Nunavut near the eastern arm of Bird Fiord. The site is called Nunavut Paleontological Expedition site NV0401, and is located 77° 10.235′ N, 86° 11.279′ West. This comprises of the Fram Formation, early Frasnian of the Late Devonian. The genus name derives from the region of Qikiqtaaluk/Qikiqtani where the fossils were discovered and the specific epithet after the late David Wake, who was a mentor and evolutionary biologist. The holotype was discovered in 2004.

## Description

The holotype is NUFV 137; a mandible, partial left upper palate that is articulated, ceratohyals, gulars and an articulated left pectoral fin and scales attaching to the dorsal, midline and flank areas. The genus is diagnosed by dorsoventral asymmetry in the pectoral fin lepidotrichia (also seen in *Tiktaalik*) and a bomerang-shaped humerus without the ventral ridge, ectepicondyle and foramina (different from *Panderichthys rhombolepis*, *Elpistostege*, *Tiktaalik* and crown tetrapods). The lack of muscular processes on the humerus for flexors and extensors at the shoulder and elbow, the terminal radial and ulnar facet position and the large fin web surface area suggests that it was less adapted for walking, trunk lifting and station holding in water than for swimming. The gracility and lack of muscle attachments to control hydrodynamics is not observed in other stem-tetrapods, and is probably apomorphous to the clade. It is 1.15m (75 centimeters) long, being smaller than most other elpistostegalians.

## Classification

*Qikiqtania* provides a plethora of characters seen in stem-tetrapods, and the lacking postaxial process on the ulnare of the pectoral fin and the defined hemitrichial asymmetry are characteristic of elpistostegalians. Jowever, the humeral morphology is distinctive and is more similar to tetrapods. This added sample size confirms that the specimen GSM 104536 is a humerus of a fishapod. This genus suggests that stem-tetrapods were far more diverse than suspected, and that they were adapting to benthic, littoral and open waters by the Late Devonian. Analysis shows that *Qikiqtania* is a distinct genus rather than a developmental stage, as the size and age variation sample in fishapods is great enough to draw conclusions. Stewart et al. (2022) find with maximum parsimony:

With Bayesian, they determine that *Tiktaalik* and *Q. wakei* form a sister clade with *Elpistostege* being crownward. However, they deem the evidence for this to be weak.

## References

* https://youtu.be/LKMvakMVcOk
* https://www.nature.com/articles/s41586-022-04990-w
Priscacara

*Priscacara* is an extinct genus of fish that lived in North America during the Eocene.

## Description

Stiff spines protected *Priscacara*'s fins, and its short jaws were crammed with tiny teeth allowing it to crush and eat snails and small crustaceans in the lakes and streams they inhabited. *Priscacara* is abundant in Eocene fossil deposits, which preserve fine amounts of soft tissue. Mass death groups suggest that *Priscacara* schooled. The fish has a flat, sunfish-like body, with a stout dorsal fin and anal spines. Species vary in anal and dorsal fin rays and in a rougher rear edge of the preopercle. *P. liops* has conical teeth in the pharyngeal, and *P. serrata* has large grinding plates.

## References

1. Dorling Kindersley Encyclopedia of Dinosaurs and Prehistoric Life, p. 51
2. https://en.wikipedia.org/wiki/Priscacara
Sonidosaurus

Credit: Andrey Atuchin.

*Sonidosaurus* is an extinct genus of titanosaur (possibly saltasaurid) that lived in Inner Mongolia during the Late Cretaceous.

## Description

*Sonidosaurus* was named by Xu, Zang, Tan, Zhao and Tan in 2006. It was small, recovered from the Iren Dabasu Formation. It was only slightly larger than *Gigantoraptor*, of which it lived with.

## References

https://en.wikipedia.org/wiki/Sonidosaurus
Styracocephalus

*Styracocephalus* is an extinct genus of tapinocephalian therapsid that lived in South Africa during the Middle Permian.

## Description

*Styracocephalus* is characterized by a backwards facing crest, two tubular horns and several sets of canines. *Styracocephalus*' crest faced up and backwards, and may have been a special trait that males had, and females lacked. The crest on individuals head was likely used for identifying other *Styracocephalus* from a distance. *Styracocephalus* had two tubular horns facing backwards on its head.

## Paleoecology

*Styracocephalus* may have been partially aquatic like that of *Hippopotamus*, but partially terrestrial.

## References

* https://en.wikipedia.org/wiki/Styracocephalus

* Archived link
Pseudogeckoolithus

A dromaeosaur among Pseudogeckoolithus eggs Credit: Julius Csotonyi.

*Pseudogeckoolithus* is an extinct oogenus of prismatic dinosaur egg that lived during the Cretaceous from the Tremp basin in Spain.

## Description

*Pseudogeckoolithus* are known from eggs of the Temp Basin, Late Cretaceous. *Pseudogeckoolithus* is named after gecko eggs, based on the nodules on the egg shell. Upon closer inspection, *Pseudogeckoolithus* eggs are nothing like gecko eggs. *Pseudogeckoolithus* represents a new group of basic fossil egg groups.

## References

https://en.wikipedia.org/wiki/Pseudogeckoolithus
Rhaphiodus

*Rhaphiodus* is a, possibly dubious, genus of goblin shark that lived in North America from the Early Cretaceous to the Miocene.

## Classification

*Rhaphiodus* was erected in 1980 based on material from *Scapanorhynchus texanus*. The publication has gone unnoticed outside of old Russian scientists. More research will need to be done to test if *Rhaphiodus* is valid.

## References

https://twitter.com/Eshanahan66/status/1285246135423184899