Batignat ( Latin Bathygnathus , from the Greek Greek βᾰθύς γνάθος “deep jaw”) is a sphenacodontic pelicosaurus from the early Permian of Polar Canada ( Prince Edward Island ). Described by Joseph Lady in 1854 on the basis of a piece of jaw from the red sandstones of this island. Leidy decided that a fragment of bone with teeth is the distal end of the right branch of the lower jaw of a large predatory dinosaur. He called it “Batignat” - “heavy jaw”, since the height of the jaw was great for its length. According to Leidi’s description, seven large teeth of unequal size were preserved in the jaw, the fragment height is more than 10 cm (4 inches), length is more than 18 cm (7.25 inches); the back of the fragment is extremely thin, which indicates that there was contact with other bones (with the arched bone, according to the author). The outer surface of the jaw is covered with a thin structure of small grooves. The teeth are flattened, resembling the teeth of modern monitor lizards. Lady noted that the teeth could be replaced from the inside out. Based on his description, Leidi concluded that the red sandstone of Prince Edward Island is Triassic. Other geologists did not completely agree with him, but the presence of dinosaur remains did not leave the possibility of a different interpretation, especially since E.D. Cope agreed with the definition of Leidi.
Alleged head reconstruction of Bathygnathus borealis
|Bathygnathus Leidy , 1854|
In 1905, E. Keyes and F. von Hunet simultaneously concluded that the jaw of the bathygnat is the left maxillary bone (maxilla) of a large predatory pelicosaurus similar to dimetrodon . Accordingly, the age of the red sandstones of Polar Canada in this region turned out to be Early Permian, which was also confirmed by the found plant remains. Judging by the size of the bone, the length of the entire skull could be up to 45-50 cm, which is comparable with the largest types of dimethrodones. It should be noted that large sphenacodonts (dimetrodon, sphenacodone , ktenospondyl ) are practically indistinguishable in the structure of the skull. Therefore, the true systematic position of the bigat within the family and its appearance (the presence of a “sail”) remains unknown. One way or another, the bathignat shows that the distribution of sphenacodonts at the beginning of the Permian period was very wide.