Baryonyx

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

## Statistics

### Diet

Carnivorous

   *Baryonyx*, previously referred to as "Claws", is an extinct genus of spinosaurid theropod dinosaur that lived in Europe during the Early Cretaceous.

## History

In January 1983, William J. Walker explored the Smokejacks Pit of the Weald Clay Formation, discovering a large claw that he assembled back at home. After realizing the tip was lost, he returned to the sit a week later and found it after an hour of searching. The second expedition also found a partial phalanx and rib. His son-in-law brought the claw to the Natural History Museum of London. Here, Alan Charig and Angela Milner identified it as a theropod dinosaur. In February, they found fragments and collected most of the skeleton in May and June due to severe weather in the pit. 8 team members and volunteers excavated 2 metric tons of matrix and 54 blocks over 3 weeks. Walker donated the claw and the Ockley Brick Company, who owned the pit, donated the remaining skeleton and necessary tools. This site had been explored for about 200 years, but there are no records of similar material being discovered. Most of the remains were crusted with Sikeston nodules and were In a matrix of fine sand, silt and clay. They were dislocated and scattered in a 5 by 2 meter area, most not far from their natural position. Certain remains were disturbed by bulldozers and others broken by machinery before discovery.

The siltstone matrix was hard and siderite was present, and thus difficult to prepare. They attempted to bathe the fossils in acid, but most was removed mechanically. Over a 6 year period of constant preparation with dental tools, aur mallets and microscopes used, they were clean. Almost 65% of the specimen was recovered, including premaxillae, left maxillae, both nasals, a left lacrimal, left prefrontal, left postorbital, the braincase and occiput, denteries, the back of the mandible, teeth, cervical, caudals and dorsals, ribs, both scapulae, both coracoids, both humeri, left radius and ulnar, finger bones and unguals, the hip, the upper end of the left and lower of the right femur, right fibula, foot bones and an ungual. This specimen was known as BMNH R9951 but is now known as NHMUK VP R9951. Charig and Milner (1986) named it then as *Baryonyx walkeri*, meaning "Walker's heavy claw". The claw was assumed to have been on the foot as in dromaeosaurs. A year earlier, the dinosaur was presented during a lecture at a conference on dinosaur systematics from Drumheller, Canada.

They then called their work preliminary because 70% of the remains were cleaned, promising a better description. *Baryonyx* was the first large Early Cretaceous theropod, the last record holder being *Eustreptospondylus*. It was featured in worldwide press and was given the nickname "Claws" (a spin of Steven Spielberg's Jaws). In 1987, a BBC documentary was made on its discovery and a cast was made for NHM's display. Charig and Milner (1987) published a monograph that intensely described the specimen — one of the most complete spinosaurid specimens known.

## Description

   Much of the middle and hind skull is unknown, with a full estimated length of 91-95 centimeters based on *Suchomimus*. It's skull is typical of baryonychines and spinosaurs: a long skull with large foramina and a premaxilla that forms a curve in the upper jaw. A subrostral notch is former by the premaxilla and maxilla articulating to form a gap. The maxilla housed the sinuses. A horny pad on the palate is indicated by a rugose texture. The nasals fused and the sagittal crest was above the eyes, which distinguishes it. The sagittal has a narrow triangular and sharp front that also distinguishes it. The lacrinal may have been a horn core, like the related and contemporaneous *Ceratosuchops*, and was nearly solid and triangular, unlike other spinosaurs. Sereno et al. thought that the names had misidentified some cranial and thus depicted the occiput as too deep, finding the skull was more low, long and narrow like *Suchomimus*. Most of the holotypic teeth were disarticulated, and few remained in the upper jaw and replacement teeth in the lower. They are recurved and cone-like, flattened from the side to create a near uniform curvature. The roots were very long and taper to the end.

* **Credit: PaleoGeekSquared on the Wikimedia Commons.**
* **Credit: Mario Lanzas.**
* **Credit: Connor Ashbridge on the Wikimedia Commons.**
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The neck was initially thought to be the typical theropod curvature but it really turned out to be a straighter S-shaped. The cervicals taper to the head and become longer as they progress backwards the zygapophyses are flat and the epipophyses are well developed. The axis was small compared to the skull and also developed well in the hyposphene. The neural arches of the cervicals are not always sutured to the central and the neural spines are low and thin. From front-to-back, the neural spines of the dorsals went from short and stout to long and broad. An isolate neural spine is elongate and slender, indicating a short sail over the back. A marked constriction in both sides of the sacral or front caudal vertebra distinguishes it. The coracoid connects with the scapula in a peg-and-notch articulation, which is an autapomorphy. The forelimbs were robust and comparatively short, with the first finger holding a claw 31 centimeters long when following the holotype's curve. Aside from the size, these claws were still clearly theropod.

## Paleobiology

Published in 2023; spinosaurid subfamilies, especially representatives of Baryonychinae, suggests that the brain structure and endocast shows no marked differences from any other common theropod; this may suggest similar behavior, especially between it and megalosaurids.

## Paleoecology

The Weald Clay Formation is Hauterivian-Barremian aged, the holotype of *Baryonyx* found in the latter. The holotype was found in a fluvial or mud flat environment that bore shallow water, lagoons and marshes. This area was covered in fresh-brackish waters, with 2 rivers draining to the north. It was subtropical, similar to the modern Mediterranean. The Smokejacks Pit has many levels that does not necessitate a taxa being contemporaneous. In this pit are ornithopods, small sauropods, crocodiles, pterosaurs, lizards, amphibians, sharks and bony fishes. Also known are insects, ostriches, isopods, conchostracans, bivalves, herbaceous plants, ferns, horsetail, club mosses and conifers. The Wessex Formation bears a diverse dinosaur fauna met with fauna much similar to the Wealden Clay. It coexistence with *Riparovenator* and *Ceratosuchops* could be a potential indicator of niche partitioning.. It was interpreted as a diving animal capable of subaqueous feeding, which was ancestral to Spinosauridae but strangely secondarily lost in it's sister taxon, *Suchomimus*.

## Classification

A distal claw fragment about 5 centimeters long and in the private hands of Martin Simpson. Munt and Hutt refer to it as "Weenyonyx", but it may actually be a juvenile *Baryonyx*. However, Darren Naish states that it can not be confirmed as a theropod. The name started as only a nickname until Molina-Perex and Larramendi (2019) published the name in a visual theropod faunal list. Additionally, the publication of *Ceratosuchops* and *Riparovenator* make this even more complicated. Apparently it is the fragmented end of an adult *Baryonyx* claw.

## References

1. ↑ https://www.theropoddatabase.com/Megalosauroidea.htm
2. ↑ https://twitter.com/TetZoo/status/1459998954603651075
3. ↑ https://twitter.com/TetZoo/status/1437512520475025418
4. ↑ https://www.nature.com/articles/324359a0
5. ↑ https://pubmed.ncbi.nlm.nih.gov/3785404/
6. ↑ https://www.researchgate.net/figure/Lateral-and-ventral-views-of-Baryonyx-walkeri-NHMUK-VP-R9951-through-the-stages-of\_fig9\_236978688
7. ↑ https://archive.org/details/princetonfieldgu0000paul/page/87
8. ↑ https://pubmed.ncbi.nlm.nih.gov/36781174/
9. ↑ https://www.youtube.com/watch?v=Y4qw545E6C0
10. ↑ https://onlinelibrary.wiley.com/doi/10.1111/joa.13837
11. ↑ https://blog.everythingdinosaur.com/blog/\_archives/2023/02/14/spinosaurs-modified-skulls-but-conservative-brains.html
12. ↑ https://www.eurekalert.org/news-releases/979404
13. ↑ https://www.nhm.ac.uk/discover/how-did-baryonyx-change-what-we-knew-about-spinosaurs.html
14. ↑ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4703214/
15. ↑ https://www.nature.com/articles/s41586-022-04528-0
16. ↑ https://www.nationalgeographic.com/science/article/spinosaurus-had-penguin-like-bones-a-sign-of-hunting-underwater
17. ↑ https://phys.org/news/2022-03-dense-bones-spinosaurus-underwater.html
18. ↑ https://www.sciencenews.org/article/spinosaurus-bones-dinosaur-swim-paleontology
19. ↑ https://twitter.com/TetZoo/status/1459998954603651075
20. ↑ https://www.theropoddatabase.com/Megalosauroidea.htm
21. ↑ https://www.degruyter.com/document/doi/10.1515/9780691190594-013/pdf