User:Horus-Horakhty/sandbox

Palaeophis is an extinct genus of aquatic snake belonging to the extinct snake family Palaeophiidae.

Described species within this genus lived mainly during the Eocene epoch, with some unnamed or questionable records from the Cenomanian, Maastrichtian and the Palaeocene.

Description
From the ancient greek παλαιός, palaiós (« ancient ») et ὄφις, óphis (« snake »), Palaeophis was originally described by Richard Owen in 1841, using fossils of the species P. toliapicus from the London Clay. It is one of the first genus of fossil snake known.

Anatomy
As in most fossil snakes species, the anatomy of the genus is known solely through vertebrae and ribs, isolated or articulated. Their morphology reveals a strong modification, due to the high aquatic specialisation of these animals. No skull elements have been described yet.

Vertebrae
The vertebrae are characterised by a marked lateral compression, a tall and thin neural spine (rarely preserved on fossils), a horizontal condyle axis, synapophyses (ribs connexion area) low on the centrum, a hypapophysis (bony projection below the vertebra) occurs on all trunk vertebrae, preceding a second anterior hypapophysis on the anterior trunk region only. The pterapophysis, bony posterior projections of the neural arch and characteristic of the Palaeophiidae, can be more or strongly defined, depending on the species. Differing from the genus Pterosphenus, the neural spine does not extends to the front of the zygosphene in Palaeophis.

The vertebrae can have an overall robust morphology, as seen in P. colossaeus or P. maghrebianus, or more slender and lightly built, as in P. toliapicus and P. typhaeus, without however reaching the more extreme morphology of Pterosphenus. The many species of Palaeophis can thus be separated into two assemblages of species or grades. In which the primitive grade include species whose vertebrae are weakly laterally compressed and have less developed and low process of vertebrae. Subsequently the advanced grade are characterized by vertebrae presenting a strong lateral compression which translate to being much better adaption to aquatic life.

Ribs
The ribs are slender, long and barely curved, giving a laterally flattened shape to the whole body of the snake, reminiscing of the overall appearance of extant Hydrophiinae sea snakes. This "eel-like" morphology enable efficient active propulsion of the animal in the aquatic environment, using its body as a fin.

Microanatomy and metabolism
The internal anatomy of vertebrae from P. maghrebianus show a high degree of internal vascularisation, superior to the one of the green anaconda or the reticulated python, suggesting a quick growth and a fastest metabolism than any of today's biggest snakes. Traces of osteosclerosis have also been observed in P. maghrabianus, and while not found in the species P. colossaeus, P. toliapicus and P. typhaeus, could be an eventual proof of its adaptation to a shallow water environment.

Size estimations
Snakes of the genus Palaeophis varied broadly in size, starting with Palaeophis casei being the smallest at 1.6 m of length, but most of them were overall imposing animals. The largest species, Palaeophis colossaeus, is estimated to have been 8.1 - 12.3 m long based on isolated vertebrae, making it the second biggest snake known, after Titanoboa cerrejonensis. P. maghrebianus was estimated at a slightly inferior or similar size. Based on more or less complete vertebrae, simulation models applied to P. africanus reveal a length of 4.3 - 6.5 m for the biggest specimens.

Ecology and behaviour
Based on the highly fragmentary nature of Palaeophis fossils, few interpretations about the ethology of the genus can be made apart from its strong aquatic specialisation. Often found associated with fossils of fish, sirenians, turtles, crocodiles, lizards, terrestrial mammals and other snakes, Palaeophis could have been an opportunistic active predator or an exclusive piscivore.

Habitat and repartition
There is an overall global repartition of the genus Palaeophis through the beginning of the Paleogene, with fossils found in Angola (P. africanus), Belgium (P. toliapicus, P. typhaeus), Denmark (P. toliapicus), England (P. toliapicus, P. typhaeus), France (P. toliapicus, P. typhaeus), India (P. vastaniensis), Italy (P. oweni), Kazakhstan (P. nessovi, P. zhylan), Kyrgyzstan (P. ferganicus), Mali (P. colossaeus), Morocco (P. maghrebianus), Nigeria (P. africanus), Togo (P. africanus), Ukraine (P. nessovi), United States (P. africanus, P. casei, P. grandis, P. littoralis, P. virginianus) and Uzbekistan (P. tamdy).

As for most Palaeophiidae, Palaeophis fossils occur primarily in shallow marine strata, though at least some estuarine remains have also been found.