recursal/Fanatic-Fandom huggingface dataset:
Stupendemys

*Stupendemys* is an extinct genus of pleurodira turtle that lived in South America from the Middle Miocene to the Pliocene.

## Description

A nearly-complete carapace measures 2.35 meters (7.7 feet) long and very wide. Another carapace, larger but not as complete, has a length of ~3.3 meters (11 feet); this would make *Stupendemys* the largest turtle to ever exist, rivaling *Archelon* in size. Small extant *Podocnemis* are closely related to *Stupendemys*. Males bear horns on each size of the carapace's neck opening. They deeply groove, which indicates a keratinous sheath. Allegedly they would have fought with these based on similar activities in their modern descendants.

## Paleobiology

*Stupendemys*, though a poor swimmer unable to move against the swift current in the small streams it likely avoided, used its weight to remain underwater for extended periods, where it grazed on the plants on the bottom. It lived in the Pebas system, which allowed it to grow to great sizes in an ~110-year lifespan. Originally, *Stupendemys* was interpreted as carnivorous, but their jaw suggests a more generalist diet, possible durophagy or frugivory.

## Paleoecology

*Stupendemys* lived in the Pebas system, and though known from fossil sites with rich fauna, has a poorly understood ecology. It swam with catfish, characids, lungfish, trahiras, freshwater rays, sharks and large crocodilians. It was contemporaneous with other turtles and tortoises. River dolphins and waterbirds were also present by water. On land, ground sloths, toxodonts, proterotheriids and caviomorphs lived, many of which were exceptionally large. Of the smaller mammals, monkeys and bats lived. Thus, this ecosystem lacks many terrestrial carnivores, so it was likely a mostly low-lying rainforest that would seasonally flood the floodplains and swampland. The wide and slow rivers hosted many large organisms and fossilferous alluvial deposits do not show evidence for fast-moving rivers, since there is no deep erosion into the sediment with little deposition.

## References

https://en.wikipedia.org/wiki/Stupendemys
Puercosuchus

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

## Statistics

### Diet

Herbivorous

*Puercosuchus* is an extinct genus of azendohsaurid reptile that lived in Arizona during the Late Triassic.

## Description

This taxon is known from partial skeletons and isolate remains that were previously assigned to *Malerisaurus* or similar taxa. This azendohsaurid is early-diverging and late-surviving and is differentiated by many autapomorphies. Over 900 skeletal remains have been collected from a minimum of 9 individuals of different size. Teeth from the Lower Chinle can be referred to this taxon based on dentigerous elements.

## References

https://vertpaleo.org/wp-content/uploads/2021/10/SVP\_2021\_VirtualBook\_final.pdf
Psalidocyon

*Psalidocyon* is a genus of canid that lived during the Early/Middle Miocene.

## History

It was named in a systematic review of Boraphaginae, after Marian Galusha, worker at the Frick Laboratory that contributed to work in the field and in the office. The holotype is F:AM 27397, a skull with I2-M2, a mandible with i1-m3, a partial scapula, a humerus, a femur, a tibia and a partial manus and near-complete pes that may not be referrable to the same taxon. They were discovered from southeast White Operation, Skull Ridge Member of the early Barstovian Tesuque Formation. Additional referred specimens from the early Barstovian Olcott Formation of Sioux County are: F:AM 25490, a partial right ramus including c1-p4 (with a broken m1); F:AM 61295, a left partial ramus including i1-p1 and p2-m1; F:AM 61296, a right partial ramus including m1, m2 and m3 alveolus; F:AM 61297, a left partial ramus with i2-m1 (with broken p1-p2 series); and F:AM 61298, a right partial ramus including m1-m2 and m3 alveolus. These were discovered at Trojan Quarry (Quarry 4, Horizon A), Humbug Quarry, Echo Quarry (for 61296 and 61297) and Quarry 2, respectively.

## Description

*Psalidocyon* was a medium size and was adapted for a heavy meat-based diet. It was named in a systematic review of Boraphaginae. A diagnosable synapomorphy shared with *Microtomarctus* and derived taxa is a pronounced P4 parastyle, which is not seen in plesiomorphous species. Other novel derived characters are tall-crowned "complex" incisors, compressed and concave lingual surface on the large canine, the presence of the antero- and posterolingual crest, the P1-P3 and p1-p4 having tall crowns with angular anter-/posterior blades, a very open m1 trigonid with a sectorial paraconid-protoconid blade, a very large metaconid on the m1 trigonid that is considerably taller than the protoconid and a horizontal ramus that is deep. Relative to *Microtomarctus*, the extended lambdoidal crests and posteriorly restricted nuchal crest are plesiomorphies.

## References

* https://en.wikipedia.org/wiki/Psalidocyon
* https://digitalcommons.unl.edu/cgi/viewcontent.cgi?referer=&httpsredir=1&article=1288&context=museummammalogy
Sanmiguelia

Before formal naming or identification, this organism was known as the following on this wiki:
**Moenave water plant** and **Pseudo-lily pad**

## Sanmiguelia

A Sanmiguelia from the Moenave, initially misidentified as a stingray and then as an unidentified plant.

## Statistics

### Height

61 centimeters

*Sanmiguelia* is a genus of angiosperm ichnogenus that lived in North America from the Late Triassic to Early Jurassic.

## History

One *Sanmiguelia* was found on the top track layer of St. George, which was misidentified by Jim Kirkland as a stingray fossil. However, paleobotanist Sidney Roy Ash pointed out the trace was either a liverwort or a closely-related group. A cast of the specimen exists, but it and photos are all that remain, as the specimen was left to the elements and eroded by wind. Kirkland later hypothesized this plant was a liverwort relative that had grown so large it was unrecognizable; it was later identified as *Sanmiguelia*.

## Description

The plant is reminiscent of palm leaves each leaf is elliptical and can measure up to 40 centimeters long and 25 centimeters inches wide, although most plants are far shorter. *Sanmiguelia* most likely represents one of the oldest Angiosperms to date, although it's exact taxonomic place within Angiosperms cannot be determined. It is known from the Chinle and Moenave. *C. lewisi* is named after St. Miguel Lewis. Each leaf sits atop a slim stem that tapers. It bears a resemblance to the extant *Acetabularia* algae.

ZNP 43201 is the youngest occurrence of *Sanmiguelia*, known from the Uppermost Whitmore Point, Lower Hettangian-aged Zion National Park. It was described by Ash et al. (2014). Aside from here, it is known from 10 other localities at the Lowermost Chinle. In total, including another, 12 localities providing *Sanmiguelia* are known in total.

## References

1. ↑ https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=414260
2. ↑ https://www.youtube.com/watch?v=-ngjvqJWwZI&ab\_channel=UtahFriendsofPaleontology
3. ↑ https://www.nps.gov/zion/learn/nature/sanmiguelia.htm
4. ↑ https://en.wikipedia.org/wiki/Sanmiguelia
5. ↑ https://www.britannica.com/plant/Sanmiguelia
6. ↑ https://twitter.com/AndrewTracks/status/1432489175220035588?s=20
7. ↑ https://twitter.com/AndrewTracks/status/1432489175220035588?s=20
8. ↑ https://twitter.com/bhalomanush/status/1429109591753822211
9. ↑ https://www.researchgate.net/publication/265550757\_First\_known\_post-Triassic\_occurrence\_of\_the\_palm-like\_plant\_fossil\_Sanmiguelia\_Brown
Stenonychosaurus

*Stenonychosaurus* is an extinct genus of troodontid dinosaur that lived in Alberta, Canada during the Late Cretaceous.

## History

Partial skulls, vertebrae, ribs, gastralia, chevrons, a sacrum, a partial pelvis and partial fore- and hindlimbs previously referred to Troodon from the Two Medicine Formation may represent a new species of this genus[*citation needed*] or may be dubious to classification. From the Egg Mountain locality of the Two Medicine, MOR 246 and other specimens, once assigned the paratypes of *Orodromeus* were reassigned to troodontids. MOR 246 is a clutch of 19 eggs and several embryos in situ.

## Description

A few factors distinguish *Stenonychosaurus* as a valid genus:

* convex anterior surface on the third metatarsal
* flat, L-shaped frontal surface with an anteroposteriorly nasofrontal contact.

In 2017, *Stenonychosaurus* was distinguished from *Troodon* with the other genus, *Latenivenatrix*. The build of *Stenonychosaurus* supported a fast running lifestyle, with sickle claws on each feet, and a mouth full of sharp teeth. Studies on *Stenonychosaurus*' inner ear and brain show it had a small degree of depth perception and was nocturnal.

## Paleoecology

*Stenonychosaurus* lived in the Dinosaur Park Formation in Alberta, Canada during the Late Cretaceous. The environment was warm, with temperate forests, and a coastal floodplain. The apex predators were *Gorgosaurus* and *Daspletosaurus*, and lived with its cousin, *Latenivenatrix*.

## Gallery

A *Stenonychosaurus* pair stumbles across the washed-up carcass of a *Tusoteuthis*.
**Credit: Mark Witton.**Skeleton of a probable *S.* sp. hunting an *Orodromeus* at the Museum of the Rockies.
## References

* https://en.wikipedia.org/wiki/Stenonychosaurus
* https://en.wikipedia.org/wiki/Two\_Medicine\_Formation
* https://en.wikipedia.org/wiki/Orodromeus
Sabinosaurus

The Sabinas hardosaurid, "sabinosaurio", "Sabinosaurus or PASAC-1, is an unnamed genus of hadrosaurid dinosaur that lived in Mexico during the Late Cretaceous.

## Description

A specimen recovered in 2001 represents this new taxon, but it is missing most of the face, which has deterred the specimen from receiving a formal name. Kirkland et al. (2006) and Prieto-Márquez (2014) have published research on PASAC-1. The Sabinas hadrosaurid is often classified near *Kritosaurus* or as *Kritosaurus* sp., although this is difficult to tell because much of the skull is missing. It is a member of Edmontosaurini.

## References

* https://equatorialminnesota.blogspot.com/2015/09/coming-attractions-in-dinosauria.html
* https://www.semanticscholar.org/paper/LARGE-HADROSAURINE-DINOSAURS-FROM-THE-LATEST-OF-Kirkland-Rivera/d8a065506b430790dfa1d4782e70193fa148054f
* https://www.sciencedirect.com/science/article/abs/pii/S0195667122001318
Saccorhytus

*Saccorhytus* is an extinct genus of deuterostome that lived during the Early Cambrian in China, Germany and the United Kingdom.

## Description

*Saccorhytus*' body is made up of a bag-like structure. *Saccorhytus* has several openings in its cylindrical body, allowing the passage of water, and potential prey. *Saccorhytus* has many thick and flexible cuticles attached to its skin. Saccorhytus lacks an anus, and may have excreted food through some other orifice. A 2022 study suggests an endysozoan affinity since the pharyngeal openings that others thought supported a deuterosome relation is taphonomic I'm origin.

## Paleoecology

*Saccorhytus* would wriggle through sand, allowing the passage of water through its pores, and capturing small prey.

## References

https://en.wikipedia.org/wiki/Saccorhytus
Rio Neuquen Pennaraptor

The Rio Neuquen Pennaraptor is an unnamed genus of pennaraptoran dinosaur that lived in Argentina during the Late Cretaceous.

## Description

The specimen is known from a partial skeleton, including a "bird-like humerus", The other 2 known pennaraptors from the Rio Neuquen with known humeri do not have a bird-like morphology.

## References

https://theropoddatabase.com/Coelurosauria.htm#Pennaraptora
Stigmellites

Stigmellites janggii holotype.

*Stigmellites* is an extinct ichnogenus of leaf-mining moth that lived in Europe during the Pliocene, Oligocene, Eocene.

## Description

*Stigmellites* bore into leaves and ate them. The appearance of *Stigmellites* is unknown. The ichnospecies *S. janggi* was named by Sohn et al. (2018) from a fossil *Fagus* which had been mined from the Early Miocene Geumgwangdong Formation of the Ponghang Basin of South Korea. It is characterized by a linear-blotch type trace, whose centric frass trail is defined and many pellets are found dispersed in the early stage of the trail. These suggest that this ichnotaxon was made by a member of Nepticulidae, being the first trophic record of this leaf and nepticulids in the Miocene and suggesting that these taxa have been associated over a long period of time.

## Species

* *S. araliae*
* *S. baltica*
* *S. carpini-orientalis*
* *S. heringi*
* *S. kzyldzharica*
* *S. messelensis*
* *S. pliotityrella*
* *S. samsonovi*
* *S. serpentina*
* *S. sharovi*
* *S. tyshchenkoi*
* *S. zelkovae*
* *S. janggii*

## References

* https://en.wikipedia.org/wiki/Stigmellites
* https://www.researchgate.net/publication/329922964\_New\_leaf-mine\_fossil\_from\_the\_Geumgwangdong\_Formation\_Pohang\_Basin\_South\_Korea\_associates\_pygmy\_moths\_Lepidoptera\_Nepticulidae\_with\_beech\_trees\_Fagaceae\_Fagus\_in\_the\_Miocene
Rhythmias

R. starrii type No. 175.

*Rhythmias* is an extinct genus of fish that lived in California during the Miocene.

## History

Originally, it was placed within Sparidae as an "ally" of the type genus, but note that further phylogenetic issues could not be resolved without teeth to analyze. The type species was named after Mr. Edward B. Starr, from the Celite Products Company, Lompoc.

## Description

The holotype of *R. starrii* is No. 175, a full-body specimen (7.5 inches) with a very damaged head, and another assigned specimen is No. 43, a large individual lacking head and compressed ~2.5 inches from it's length in life. A third specimen (13 inches) is poorly preserved, joined by an additional five specimens that are briefly described as may lack the antrorse dorsal spine. The head is large and obtuse, with an evenly-curved upper profile. Cranial bones do not show markings of serrations or spines, with short and slender intraneurals that are sometimes dilated base-wards once or twice between the neurals; the second interhaemal is enlarged, to a degree. The dorsal fin, low, is scarcely-notched and continuous. The antrose spine is lacking before the first spine, with the middle spines being highest, the second spine being strong and curved as well as raised over the third and soft rays. The pectorals are narrow and the thoracic ventrals inserted immediately behind the pectorals. Caudals one and five are forked and have elongated lobes.

## References

* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=36175
* https://www.biodiversitylibrary.org/item/71220
Sinuijumantispa

*Sinuijumantispa* is an extinct genus of drepanicine mantidfly that lived in North Korea during the Early Cretaceous.

## History

*Sinuijumantispa* was discovered in the Lower Cretaceous Sinuiju formation in Northern North Korea and described in February 2022 by North Korean Paleontologists Kwang-Sik So and Chol-Guk Won. It is the most basal member of the subfamily Drepanicinae.

## References

1. ↑ 1.0 1.1 https://www.sciencedirect.com/science/article/abs/pii/S0195667122000398
Siouxlindrodon

Credit: Michael Tripoli.

*Siouxlindrodon* is an extinct genus of cylindrodont rodent that lived in Nebraska during the Late Eocene-Early Oligocene .

## History

The genus was named by Korth et al. (2022) from the Chadron Formation. It is represented by 40 specimens found 1-6 meters below the UPW that were discovered by using extant ant colonies from the White River Group. The specific epithet is after Joseph Sullivan of the Buffalo Geological Society. SDSM 155559 (left M1/M2) and SDSM 155576 (left m1/m2) are the syntypes. SDSM 155550, 155551, 155560, 155564 (P4s), SDSM 155547-155549, 155553-155556, 155558, 155561-155563 (M1/M2s), SDSM 155552, 155557 (M3s), SDSM 155567, 155574, 155575 (p4s), SDSM 155568-155571, 155577-155587 (m1/m2), SDSM 155565, 155566 and 155572 (m3s) are the referred specimens. Clint Boyd, a coauthor of the study, commissioned many different paleoartists to produce renditions of their new taxa.

## Description

Cheek teeth that are unilaterally subhysodont and lophate, all lophids/lophs being high and thin with subdued loph cusps, ectolophs on the upper molars that continues for the length, mesostyle being absent or not developed, high and thin protolophs and metalophs that continue to the protocone, endolophids on the lower molars that run the length, the central basin is enclosed lingually, a generally incomplete ecotolophic, endolophids that are shorter and markedly lower than the endolophid, a metalophulid II on the lower molars parallel to the hypolophid are long and complete and the hypolophid lacks a p4 and variably present on the m3 define this genus. It is easily distinguished from *Cylindrodon*. It is a classic cylindrodont in that the enclosed central basin, lophodonty and crown height are unique to this family. *Lophicylindrodon* has a similar degree of lophodonty but is not as great in the unilateral degree, more discernible cusps and a lacking metalophulid on the lower molars.

## Paleoecology

It is one of over 80 taxa in the Chadron Formation and was once of 10 new taxa named in 2022. This formation dates to the Latest Eocene-Earliest Oligocene.

## References

* https://www.researchgate.net/publication/361037651\_Fossil\_mammals\_from\_ant\_mounds\_situated\_on\_exposures\_of\_the\_Big\_Cottonwood\_Creek\_Member\_of\_the\_Chadron\_Formation\_latest\_Eocene-early\_Oligocene\_Sioux\_County\_Nebraska
* https://twitter.com/boydpaleo/status/1517683122598514690
Igea Spinosaur

Credit: @proyectonublar on Twitter.

The Igea Spinosaur is an unnamed genus of Baryonychine Spinosaurid that lived in Igea, La Rioja, Spain, during the Cretaceous.

## Description

The specimen, is remarkably complete, being almost as complete as the holotype of *Baryonyx*. The photographed remains include: a partial arm, a hindlimb, a pelvic girdle, and other associated elements. There is a pathology on the fibula of the specimen's fibula.

## References

* https://twitter.com/Manu\_MB13/status/1639385472399990784
* https://twitter.com/DarioEstraviz/status/1639342747415879680
* https://twitter.com/proyectonublar/status/1639322655198175232
* https://twitter.com/TheBioBob/status/1639392402161934337
* https://twitter.com/TheBioBob/status/1639392751832776706
* https://twitter.com/TheBioBob/status/1639394268153278472
* https://twitter.com/TheBioBob/status/1639402062977937409
* https://twitter.com/TheBioBob/status/1639397385833938944
* https://fundaciondinosaurioscyl.blogspot.com/2023/03/los-restos-del-dinosaurio-espinosaurido.html
Vitakridrinda

"Vitakridrinda" is a possibly dubious and naked genus of abelisaurid theropod dinosaur that lived in Pakistan during the Late Cretaceous.

## Description

The "type" specimens are known from Pakistan, discovered by the Geological Survey of Pakistan from the Maastrichtian Vitakri Member, Pab Formation. M.S. Malkani named it in 2006, based on thigh bones, a tooth and a braincase. A partial snout was later found, assigned to the holotype by Malkani. Additionally, vertebrae may be from this set of remains. However, the snout was later assigned a new genus, "Induszalim", a mesoeucrocodylian. This genus is possibly a nomen nudum. Its size was estimated to be 6 meters (19.7 feet) by Thomas Holtz in 2012.

## 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.
MPV 2020.1.1

MPV 2020.1.1 is a possible unnamed genus of Allosaurid dinosaur that lived in France during the Late Jurassic.

## Description

The specimen is known from a partial dentary and maxilla. It was discovered in 2002 by the Anicolas family at the base of the Falaises des Vaches Noires, probably belonging to the Marnes de Dives Formation, but possibly the Marnes de Villers formation. The specimen was only partially prepared and the owners of the specimen did not allow the researchers to prepare it fully. The authors interpreted the characters visible as belonging to an indeterminate Allosaurid, however, there are more characters that align with *Sinraptor* rather than *Allosaurus*, the only uncontroversial Allosaurid. No matter what family the taxon belongs to the taxon still possesses traits that distinguish it from the other. If it is a Metriacanthosaurid instead of an Allosaurid, it would be incomparable to the holotype, and only known specimen of *Metriacantosaurus* from the contemporaneous Oxford Clay Formation.

## References

* https://twitter.com/SkyeMcDavid/status/1507055549246062601?s=20&t=lCOGPw9YJ4CBVZhDTcCfkA
* https://sciencepress.mnhn.fr/en/periodiques/geodiversitas/44/12
Sinankylosaurus

Credit: CisioPurple on DeviantArt.

*Sinankylosaurus* is an extinct genus of ankylosaur that lived in China during the Late Cretaceous.

## Description

The holotype is a partial right ilium recovered in Shandong, China. The species is similar to North American ankylosaurs, which is one of the major claims the authors point out.

## History

*Sinankylosaurus* means Chinese fused lizard; sin "Chinese" and *Ankylosaurus* "fused lizard".

## Notable Specimens

* ZJZ-183: A near-complete ilium recovered from the Wangshi Group, Shandong, China.

## References

https://en.wikipedia.org/wiki/Sinankylosaurus
Somniosus

This page is about a genus that contains extinct and extant species; species marked with † are extinct.

## Statistics

### Diet

Carnivorous

*Somniosus* is a genus of sleeper sharks that live around the Americas and Greenland since the Oligocene.

## Species

* *S. antarcticus* (southern sleeper shark)
* *S. longus* (frog shark)
* *S. microcephalus* (Greenland shark)
* *S. pacificus* (Pacific sleeper shark)
* *S. rostratus* (little sleeper shark)
* †*S. gonzalezi*
* *S. sp.* (longnose sleeper shark) (unnamed)

## References

* https://en.wikipedia.org/wiki/Somniosus
* https://www.fishbase.de/summary/138
Proanthropus

Holotype of Homo erectus.

*Proanthropus* is a dubious genus of hominin that lived in Europe, Asia and possibly North America from the Early to Late Pleistocene.

## History

The genus *Proanthropus* was used by many authors to refer to a "missing link" ancestor to *Homo sapiens*. At the time, the remains at Trinil had stirred discussion among scientists, most agreeing that it was a deformed human or a miniature *Homo neanderthalensis*. The name originated with Hermann Klaatsch and his hypothetical *Proanthropus* from the Tertiary, which served as a more derived ancestor that *Homo sapiens* and *Pithecanthropus* would have arisen from due to a degeneration process. He also thought that the latter may have been a "lower" form of *Proanthropus*, and thus not ancestral. Ludwig Wilser used the genus under a different definition: *P. erectus*, *P. neogaeus* and *P. europaeus* as extinct and *P. arctogaeus* as extant. The first of the extinct roster referring to Trinil, the second referring to an Argentinian felid fossil thought to be human and the third referring to the Pildown hoax. It is not known what the extant taxon refers to. The name *H. (P.) louisleakeyi* was a replacement name for *Homo leakeyi* (based off OH 9) by Groves (1989).

## Species

* †*P. erectus* (=Trinil)
* †*P. neogaeus*/*neogeus*
* †*P. europaeus* (=Piltdown hoax)
* *P. arctogaeus*
* †*Homo (P.) louisleakeyi*

## References

* https://books.google.ca/books?id=9xm4BgAAQBAJ&dq=%22proanthropus%22&source=gbs\_navlinks\_s
* https://books.google.ca/books?id=GJALAQAAIAAJ&vq=proanthropus&dq=%22proanthropus%22&source=gbs\_navlinks\_s
* https://books.google.ca/books?id=440TmWXToLAC&dq=%22proanthropus%22&source=gbs\_navlinks\_s
* https://link.springer.com/article/10.1007/s10739-008-9165-9?noAccess=true#citeas
Pyroraptor

Credit: Mette Aumala on the Wikimedia Commons.

*Pyroraptor* is an extinct genus of dromaeosaurid dinosaur that lived in France during the Late Cretaceous.

## History

*Pyroraptor* was discovered in 1992 after a forest fire near the Mont Olympe in Provence, Southern France. The genus was described by Ronan Allain and Philippe Taquet in 2000 based on MNHN BO 001 through 017, housed in the Muséum national d'histoire naturelle (National Museum of Natural History) in Paris, France. The holotype is MNHN BO 001, the left killing claw. The genus name *Pyroraptor* means "fire thief" in reference to its discovery after a forest fire, and the specific epithet *olympius* refers to the nearby Mont Olympe.

Since its description, *Pyroraptor* has been suggested to be a possible junior synonym of *Variraptor mechinorum.* Since *Variraptor* was named first, that name would have priority if synonymy is proven.

## References

1. ↑ 1.0 1.1 https://www.researchgate.net/publication/232672586\_A\_new\_genus\_of\_Dromaeosauridae\_Dinosauria\_Theropoda\_from\_the\_Upper\_Cretaceous\_of\_France
2. ↑ Variraptor
Rhizomnium

This page is about a genus that contains extinct and extant species; species marked with † are extinct.

## Statistics

### Location

Near-worldwide

*Rhizomnium*, or leafy mosses, is a genus of moss that have lived nearly worldwide since the Middle Eocene.

## Distribution

*Rhizomnium* grow nearly worldwide, mostly in the northern hemisphere.

## Species

* *R. andrewsianum*
* *R. appalachianum*
* *R. glabrescens*
* *R. gracile*
* *R. horikawae*
* *R. magnifolium*
* *R. nudum*
* *R. pseudopunctatum*
* *R. punctatum*
* *R. striatulum*
* †*R. dentatum*

## References

* https://en.wikipedia.org/wiki/Rhizomnium\_dentatum
* https://en.wikipedia.org/wiki/Rhizomnium
Rostropycnodus

Credit: Nix Illustration.

*Rostropycnodus* is an extinct genus of pycnodontiform that lived in Asia during the Middle Cretaceous.

## Description

*Rostropycnodus* is very similar in shape to angelfishes and butterflyfishes. The fish bears an extremely elongated shout and a reduced lower jaw. The fish has a horn on its head, a bulbous pectoral region and pectoral fins that modified into large spines. *Rostropycnodus* has very short pelvic fins that sit below a pair of large spines. *Rostropycnodus* was likely a very slow swimmer, that used its overall defense to deter predators. *Rostropycnodus*, unlike most pycnodonts, had a toothless mouth, so it may have probed sediment or small cracks with its rostrum in search of small defenseless organisms.

## References

https://nixillustration.com/science-illustration/2019/rostropycnodus/
Protopteryx

Credit: SmallMicrorapterr on Twitter.

*Protopteryx* is an extinct genus of enantiornithean bird that lived in China during the Early Cretaceous.

## Description

*Protopteryx* is named after its feathers, which are more primitive than other enentiornithean birds: lacking barbs and rami. *Protopteryx* had conical and unserrated teeth, some having a resorption pit similar to ones in *Archaeopteryx*. Its body was coated in three distinct types of feathers: downy, flight and long tail feathers. Most feathers were 12 millimeters (0.47 inches). The barbs of the downy feathers are laminar, rather than hair-like, and were frayed at the tips. The most distinctive feature of *Protopteryx* is the ribbon-like tail feathers, which consisted of two feathers and were barbed at their tips. However, closer to the body, feathers were thin, and needle-like. The only extant bird to share this feature is the red bird-of-paradise.

With all these feather adaptations, *Protopteryx* was adapted to flying like modern birds. This is reflected in the birds procoracoid, sternum, external tuberosity and humerus and deltoid crest. *Protopteryx* had a modern supercaracoideus and pectoralis. *Protopteryx* has asymmetrical flight feathers with flying birds, as in *Archaeopteryx* and *Confuciusornis*. The tail feathers lack of rami shows that they were used for thermoregulation, display, and sensory usages. The wing tips preserve black feather pigment

## References

https://en.wikipedia.org/wiki/Protopteryx
Spectrovenator

Credit: Sergey Krasovskiy.

*Spectrovenator* is an extinct genus of abelisaur that lived in Brazil during the Early Cretaceous.

## Description

*Spectrovenator* lacks the intramandibular kinetic joint and the dorsal projection on the parietals that resembles a button. Among these features that place *Spectrovenator* at a more basal spot, *Spectrovenator* had very large cheeks which curve down past their jaws and down to the bottom of its mandible.

*Spectrovenator* was found buried under remains of *Tapuisaurus*.

## References

http://sciencepress.mnhn.fr/fr/periodiques/comptes-rendus-palevol/19/6
Protostega

Credit: Andrey Atuchin.

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

## Description

*Protostega* is the second largest turtle that ever existed, being 3 meters (9.8 feet) long, only beat by *Archelon* and longer than *Stupendemys*. *Protostega*'s shell lacked ossification, which helped bring the animal down in weight and streamline it for open-ocean travel. The carapace itself was extremely reduced, extending only half the distance to the distal rib-endings. Cope originally described modified bones, including an elongate coracoid process that stretched towards the pelvis and humerus, like *Dermochelys*, the leatherback sea turtle. This feature creates a greater movement range for the animals limbs in life. Protostega has a very large jugal, which stretches to the quadrate and a thickened pterygoid, which itself reaches over to the mandibular articulating point at the quadrate. The holotype specimen features a prominent reduction in the posterior segment of the vomer, where palatines medially-meet. *Protostega* had an unusually small beak, which was considerably larger in certain individuals. The premaxillary beak was much shorter than in *Archelon*. The front of the orbits and associated areas was an elongate and broadly roofed temporal region. The animals beak is built strongly, and broad. This gave the jaws the surface area needed to crush shelled organisms under their weight. The quadrato-jugal is triangular, sporting a concave posterior edge, the entire bone being convex in shape from the distal viewpoint. The squamosal bone appears to have a concave structure on the upper end of the quadrate. The holotypes mandible is nearly perfectly preserved, and was described as similar in shape and in structure to Chelonidae. *Protostega*'s dentary is broad above and concave below. This concave surface is marked by many deep pits. The long symphasis in its lower jaw means that *Protostega* was likely omnivorous, consisting of crustaceans, jellyfish, floating carcasses and seaweed, like many modern turtles. One specimen of *Protostega* exhibits a flipper spans of 1.5 meters (5 feet) long, and was a juvenile at death.

One specimen housed at the Rocky Mountain Dinosaur Resource Center in Colorado. This specimen is the first of *Protostega* sp., an unnamed specimen or possibly a juvenile.

## Paleoecology

*Protostega* lived in high temperatures, as marked by the Late Cretaceous and inhabited large epicontinental seaways. Most popularly, the Western Interior Seaway.
Sam Ran Spinosaurid

Skeletal from the report

The Sam Ran Spinosaurid is an unnamed genus of Spinosaurid Dinosaur that lived in Thailand during the Early Cretaceous.

## Description

During an expedition to the Sam Ran locality in 2004 the team at the Sirindhorn Museum discovered fragmentary material for 17 specimens of Spinosaurids. This includes 4 cervical vertebrae (3 complete, one fragmentary, 2 dorsal vertebrae, one including most of the neural spine, 3 neural spines, of varying levels of completeness, 3 ribs, 1 caudal chevron, a mostly complete ischium and pubis, a partial radius, and metacapral II. Chowchuvech tentatively referred the taxon to Spinosauridae indet. because, "in this project I've provided only a preliminary taxonomic study by morphological comparison on this specimens. So, I hope that there’ll be a properly phylogenetic analysis on this materials soon." It is likely that this genus is either partially or completely synonymous with *Siamosaurus suteethorni*, however, Spinosaurid tooth taxon are not diagnostic and should not be used to name taxa. As it stands *Siamosaurus* is an indeterminate Spinosaurid and if this taxa is named as a new genus it will most likely take precedence over *Siamosaurus*.

## Phylogeny

If the Sam Ran Spinosaurid is the same as *Siamosaurus,* it is possible that it will be recovered in a similar phylogenetic position; however, this is uncertain because the Sam Ran Spinosaurid is more complete and has more scorable material than *Siamosaurus*. This cladogram was recovered by Arden et. al. (2019), Siamosaurus has been replaced by The Sam Ran Spinosaurid.

## References

* https://twitter.com/JobSaurusRex/status/1514222461461889029?s=20&t=xFoJ4hYzlnHCaZ2-DylpgA
* https://twitter.com/JobSaurusRex/status/1514222469942775809?s=20&t=xFoJ4hYzlnHCaZ2-DylpgA
* https://twitter.com/JobSaurusRex/status/1514222479799361538?s=20&t=xFoJ4hYzlnHCaZ2-DylpgA
* https://twitter.com/JobSaurusRex/status/1514222488397684745?s=20&t=xFoJ4hYzlnHCaZ2-DylpgA
* https://twitter.com/JobSaurusRex/status/1514222497394475014?s=20&t=xFoJ4hYzlnHCaZ2-DylpgA
* https://twitter.com/JobSaurusRex/status/1514222508308037634?s=20&t=xFoJ4hYzlnHCaZ2-DylpgA
* Thomas M.S. Arden, Catherine G. Klein, Samir Zouhri, Nicholas R. Longrich, Aquatic adaptation in the skull of carnivorous dinosaurs (Theropoda: Spinosauridae) and the evolution of aquatic habits in spinosaurids, Cretaceous Research, Volume 93, 2019, Pages 275-284, ISSN 0195-6671, https://doi.org/10.1016/j.cretres.2018.06.013. (https://www.sciencedirect.com/science/article/pii/S0195667117303427)
Shansaraiki

"Shansaraiki" is a naked-named genus of ?abelisauroid dinosaur that lived in Pakistan during the Late Cretaceous.

## History

Named from GSP/ MSM-140-3 (symphysis), GSP/MSM-5-3 (mid-ramus with partial teeth bases) and GSP/MSM-57-3 (dorsal vertebrae) that were found from various areas within the Vitakri dome. Doubts about these remains connectiveness and validity has been raised, since they were found apart and are extremely fragmentary.

## References

* https://twitter.com/TylerGreenfieId/status/1599833793980141568
* https://www.scirp.org/journal/paperinformation.aspx?paperid=121611
SM 2012-1-021

Photographs of the specimen in various positions.

SM 2012-1-021 is an unnamed genus of sawskate that lived in Thailand during the Early Cretaceous.

## Description

SM 2012-1-021 is known from a single rostral denticle, with the tip of the denticle having enameloid droplets, which hasn't been found in any other Sclerorhynchoid. The formation SM 2012-1-021 comes from, the Sao Khua Formation, is dated to the Barremian, making this taxon one of the oldest, with the only other Sclerorhynchoids from the Barremian being *Celtipristis* and *Onchopristis.* After SM 2012-1-021 was collected an extensive screen-washing campaign was underwent to try and find similar fossils, but has yet to provide a second specimen. The researchers found this unusual because Sclerorhynchoids aren't usually too rare. Because it is so rare, that means this taxon was possibly very uncommon within the region and may have fossilized by sheer happenstance. The authors also state that this specimen could have been a hybodont cephalic spine, but for various reasons affirm that it is almost definitely Sclerorhynchoid.

## References

* https://en.wikipedia.org/wiki/Sclerorhynchoidei
* https://en.wikipedia.org/wiki/Sao\_Khua\_sclerorhynchoid
* https://twitter.com/TylerGreenfieId/status/1487485888821141505
* https://www.researchgate.net/publication/274699139\_A\_SCLERORHYNCHOID\_CHONDRICHTHYES\_BATOMORPHII\_IN\_THE\_LOWER\_CRETACEOUS\_OF\_THAILAND
Sahonachelys

Credit: Andrey Atuchin.

*Sahonochelys* is an extinct genus of pleurodiran turtle that lived in Madagascar during the Late Cretaceous.

## History

The holotype, UA 10581, was discovered in June 2015 within the Maastrichtian-aged Maevarano Formation in the Mahajanga Basin during the removal of the overburden less than a meter above an archosaur-rich layer. It is a well-preserved skeleton with a skull, partial hyoid, limbs, shoulders and vertebrae. In 2021, it was named. *Sahonachelys* means "frog turtle". *M. mailakavava* derives from the Malagasy "mailaka" (quick) and "vava" (mouth), the full name translates to "quick-mouthed frog turtle".

## Description

—Dr. David Krause, a paleontologist in the Department of Earth Sciences at the Denver Museum of Nature & Science and the Department of Anatomical Sciences at Stony Brook University
*Sahonachelys mailakavava* lived in Maastrichtian Madagascar, 72-66 million years ago. As turtles do, this species lacks teeth, with the surfaces at the top and bottom jaws being poorly developed, facing one-another. This shows that the animal was incapable of processing food, sucking in prey whole. It likely fed on small-bodied living prey, such as insect larvae, fish and tadpoles, striking quickly. The turtle had a gracile lower jaw and large tongue bones, giving the animal a frog-like appearance, being a specialized suction feeder that fed upon live, moving prey. It's skull was flattened. This is not seen in other pelomeduscoids, which isolate the Madagascaran fauna as having evolved in isolation.

## Classification

Joyce et al. placed it into a new family as sister to *Sokatra*, Sahonachelyidae, due to the reduced maxillary contribution to the orbital floor and the distinct posterior process of the maxilla. This entire clade is sister to the Podocnemididae-Bothremydidae joint clade.

## References

1. ↑ 1.0 1.1 1.2 https://en.wikipedia.org/wiki/Sahonachelys
2. ↑ http://www.sci-news.com/paleontology/sahonachelys-mailakavava-09625.html
Pops

Pops is an unnamed genus or species of Triceratopsini Ceratopsian that lived in Colorado during the Late Cretaceous.

## Description

—Joe Sertich
Pops is known from a partial skull and as of yet undescribed post-cranial elements, including vertebrae and pieces of tailbone. it was discovered in Weld County, Colorado. It was housed in the county Courthouse for 34 years until Joe Sertich and DMNS started working with the county to fully prep and describe the specimen. At first, paleontologists believed that this specimen represented the earliest occurrence of *Triceratops,* however, with further analysis, Sertich realized that this specimen was unlikely to be *Triceratops*. Various parts of the anatomy align with *Eotriceratops*, including the shape of the nostral flange.

## References

* https://www.youtube.com/watch?v=NguZJ3QSPh4&t=133s
* https://www.discoverweld.com/Pops-the-Triceratops
* https://www.kunc.org/science/2021-02-08/old-bones-new-story-the-tale-of-a-dinosaur-named-pops
* https://youtu.be/Qr7u0U4u5bo
Protocyon

Credit: HodariNundu on DeviantArt.

*Protocyon* is an extinct genus of canid that lived in the Americas from the Late Pliocene to the Late Pleistocene.

## History

*P. orocualensis* was named in a 2022 article by Damin Ruiz, Xiaoming Wang and Ascanio Rincón on Venezuelan canids.

## Description

The dentition of specimens suggest that Protocyon was a hypercarnivore and hunted medium sized animals and young megafauna. *P. orocualensis* was named in 2021 and was about 23 kilograms heavy. It was named from a mandible, Or-1332, recovered from the Late Pliocene/Early Pleistocene the El Breal de Orocual asphalt pit, east Venezuela. This makes this species one of the earliest South American canid.

It was hyoercarnivorous and likely a pack hunter that hunted medium-sized grazers and browsers such as *Glyptotherium*. A molar from Santa Vitória do Palmar suggests a weight of 23-37 kilograms (55-82 pounds) for this individual. It was coined by Giebel (1855) and placed into Canidae by Carroll (1988). As part of Cerdocyonina, *Lycaon* may be related. Finds are known from Bolovia, Buenos Aires, Argentina, Santa Elena Peninsula, Uruguay, Mene de Inciarte Tar Seep, Mexico and Brazil. Coyote remains from the Hoyo Negro pit in Sac Actun cave system were reidentified as *P. troglodytes* by Schubert (2019), suggesting occurrence in southern North America.

## References

* https://en.wikipedia.org/wiki/Protocyon
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=41238
* https://www.ameghiniana.org.ar/index.php/ameghiniana/article/view/3448
Sulaimanisuchus

Sulaimanisuchus is a naked genus of mesoeucrocodilian that lived in Pakistan during the Late Cretaceous.

## Description

Sulaimanisuchus is represented by holotype dentary GSP/MSM-63-4 and proximal humerus GSP/MSM-1094-4, found at the surface ~5 meters apart.

## References

https://www.researchgate.net/publication/353701905\_Formal\_description\_of\_poripuchian\_titanosaurs\_theropods\_mesoeucrocodiles\_pterosaur\_snake\_and\_bird\_from\_the\_latest\_Maastrichtian\_Vitakri\_Formation\_of\_Pakistan
Rodrigues Solitaire

## Pezophaps

Credit: Nix Illustration.

The Rodrigues Solitaire, genus *Pezophaps*, is an extinct genus of bird that lived on the island of Rodrigues and went extinct during the 19th century.

## Description

The Rodrigues Solitaire is a flightless bird, with long tilt-like legs, small wings and a sharp beak. *Pezophaps* have plump bodies, like their close cousin *Raphus*.

## Paleoecology

The Rodrigues Solitaire likely ate dates. The island *Pezophaps* lived on was soon found by french sailors and a colony was built on the island. *Pezophaps* and *Raphus* make up the family of Raphinae.

## Extinction

The Rodrigues Solitaire likely went extinct between 1730-1760. Colonists on the island burnt leaves, hunted Rodrigues Solitaires and sent cats out to eat their eggs and hatchlings. The *Pezophaps* species was impacted largely by the sailors actions. A French engineer Joseph-François Charpentier de Cossigny attempted to reassure the sailors that the animal still lived in very remote parts of the island. The man tried for 18 months, but to no avail. He thought that the cats unleashed into the jungle were to blame for destroying the population, but also suspected the human presence. Many individuals tried to prove the existence of the bird. Colonizers on the island fail to recall seeing any large birds, which is strange because the size of them would have been hard to go undetected. A man that lived 40 years on the island does not recall any large species of bird.

## Synonyms

* *Didus solitarius*
* *P. solitarius*
* *Didus nazarenus*
* *P. minor*

## References

* https://en.wikipedia.org/wiki/Rodrigues\_solitaire
LACM 149371

LACM 149371 is a presumably undescribed genus of rodents that lived in Peru during the Late Eocene or Oligocene.

## Description

LACM 149371's teeth are cusped, and appear to be molars. The teeth lack enamel. LACM 149371 tooth crowns have six cusps in total. The roots of the tooth are chipped away, but the pulp cavities remain.

## References

https://en.wikipedia.org/wiki/LACM\_149371
Potomac River gomphothere

A possible enamel fragment from this taxon.

The Potomac River gomphothere is an unnamed genus of gomphothere that lived in Virginia during the Miocene.

## Description

This species is known by partial left and right mandibles with m2-m3's with partial upper and lower tisls from a cliff along Potomac River, CI2 Choptank Formation. The tusks look like typical *Gomphotherium* but the cheek teeth have many differences; the m2 is strongly double-trefoiled and incipiently tetralophodont with a large conulid and the m3 is elongate with 5 lophids with partially-suppressed single trefoiling but only weakly on the first 2 lophids. These are enough to distinguish it on the genus level, most closely resembling *Pediolophodon*, which also has an elongate m3 with partially-suppressed single trefoiling. An enamel fragment recovered from Potomac River was put on the FossilForum, identified as a chunk from a gomphothere tooth, and may be a part of this taxon.

## References

* https://vertpaleo.org/wp-content/uploads/2021/10/SVP\_2021\_VirtualBook\_final.pdf
* http://www.thefossilforum.com/index.php?/topic/109149-odd-chunk-of-enamel-stratford-hall/
Saivodus

Credit: HodariNundu on DeviantArt.

*Saivodus* is an extinct genus of ctenacanthiform sharks that lived in Kentucky, Alabama and Arizona during the Early Carboniferous.

## Discovery

The most notable *Saivodus* was found on the cave ceiling of Mammoth Cave National Park. Multiple remains were found around this specimen.

## Description

*Saivodus* lived in a time where ctenacanth sharks were at their greatest diversity, spanning the globe worldwide. This shark also belonged to a group of sharks known for their flat jaws and fins with unique ornamentation sprouting as a defense. Teeth from Saivodus are mostly found on their own, with some accompanying the larger whole specimen. Some exceed 6 centimeters in length at the base, which is larger than the modern great white.

Lodged in the cave wall is skull, is the noticeable mandible, which is 2.5 feet long, many loose teeth dislodged in loose sediment on the cave's floor, and a single vertebrae mixed with the cranium. Among these are remains from other marine fauna from the time, meaning the shark was likely scavenged. The chin exposes from the rock, with approximately 5 teeth also exposed. Most of the latter are tooth roots, with one exposing the crown and curves backwards, suggesting it was a back tooth. These teeth are between 3 and 3.5 centimeters (1.5+ inches) in width. A small spine sits among the remain, belonging to a smaller creature. Parts of the remains have miscellaneous cranial and cartilage material, and the back of the lower jaw is excluded. The left half of the mandible as the mandibular knob pointing outwards, meaning the piece belongs to the left element. The ventral mandibular ridge is visible. This specimen preserves elements of cartilage.

## Synonyms

* *Cladodus caorrugatus*
* *Cladodus eccentricus*
* *Cladodus elongatus*
* *Cladodus ferox*
* *Cladodus grandis*
* *Cladodus hornei*
* *Cladodus magnificus*
* *Cladodus prototypus*
* *Cladodus spinosus*
* *Cladodus stenopus*
* *Cladodus striatus*

## Paleoecology

The Mammoth Cave specimen likely sunk to the ocean floor, to which the carcass would have been swarmed by smaller bottom-dwelling carnivores. The body would have been a hotspot for smaller sharks, as remains of other animals are mixed with Saivodus. Teeth of *Bransonella*, *Falcatus*, the eel-like *Thrinacodus*, as well as the dorsal spine of a smaller shark have all been excavated from the same locality. The remains were also disturbed at discovery, as several elements are mixed and dismembered, covering with sediment to preserve the feeding-frenzy.

## References

* https://www.nps.gov/articles/000/shark-fossil-saivodus-striatus.htm
* https://shark-references.com/species/view/Saivodus-striatus
* https://paleobiodb.org/classic/basicTaxonInfo?taxon\_no=149834
Smitanosaurus

Before formal naming or identification, this organism was known as the following on this wiki:
**USNM 5384**

## Statistics

### Diet

Herbivorous

Smitanosaurus is an extinct genus of dicraeosaurid sauropod that lived in Colorado during the Late Jurassic.

## History

Marsh (1889) named a partial cranium, proatlases and three cervicals *Morosaurus agilis*, discovered from the Morrison Formation of Colorado in 1883. However, the common consensus at the time was that this genus was synonymous with Camarasaurus, but this taxon in specific was left without generic assessment. At the time, it was compared with Haplocanthosaurus, Diplodocus and brachiosaurids. Until Whitlock and Wilson (2020) analyzed, named and entered into a phylogenetic analysis. They found it was a dicraeosaurid and coined the name "Smith lizard" after J. August Smith, excavator who sketched the holotype, USNM 5384, and after the Smithsonian Institution, where the holotype is deposited.

## References

https://en.wikipedia.org/wiki/Smitanosaurus
Raptorex

Raptorex is a genus of tyrannosaurid from the Cretaceous Period of Asia. Its exact temporal range is unknown; it could have lived during the Early Cretaceous or the Late Cretaceous, but this is not settled. Raptorex was very small for a tyrannosaurid, but it had all the key traits of the group: small arms, large brain, and bone crushing jaws. Due to the disputed temporal range, its exact prey is hard to decipher. It actually may have not been a true tyrannosaurid, but a more basal tyrannosauroid, in which case such a small size would not be unusual.