Palaeophis

These species varied broadly in size; Palaeophis casei is the smallest at 1.3 metres of length, while the largest species, Palaeophis colossaeus, is estimated to have been long based on isolated vertebrae, making it one of the largest known snakes. However, most species of the genus were not as big. There are many species of Palaeophis but they can 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 adapted to aquatic life. ==Biology==

Species of Palaeophis were specialised aquatic animals, as their fossils occur primarily in marine strata, though at least some estuarine remains have also been found. Studies on Palaeophis vertebrae show a high degree of vascularisation, suggesting that it had a considerably faster metabolism and growth rate than modern snakes. This may suggest that palaeophiids, like other marine reptiles such as mosasaurs, might have developed towards endothermy. ==References==