Teleosaurs ( lat. Teleosaurus , from other Greek. Τέλειος σαῦρος "the perfect lizard") - an extinct genus of crocodilomorphic creatures from the family of teleosaurids , who lived on Earth in the Middle Jurassic era .
| † Teleosaurs |
|
| Scientific classification |
|---|
| No rank : | Bilateral symmetrical |
| Infraclass : | Archosauromorphs |
| No rank : | Archosauriformes |
| Squadron : | Crocodilomorphs |
| Suborder : | † Talattosuchia |
|
| International scientific name |
|---|
Teleosaurus Geoffroy , 1825 |
| Kinds |
|---|
- T. cadomensis Lamouroux , 1920 typus
- T. asthenodeirus Owen , 1842
- T. megarhinus Hulke , 1871
- T. geoffroyi
|
Geochronology203-175 Ma | million years | Period | Era | Aeon |
|---|
| 2,588 | Even | | | Ka | F
but
n
e
R
about
s
about
th | | 23.03 | Neogene | | 66.0 | Paleogen | | 145.5 | a piece of chalk | M
e
s
about
s
about
th | | 199.6 | Yura | | 251 | Triassic | | 299 | Permian | P
but
l
e
about
s
about
th | | 359.2 | Carbon | | 416 | Devonian | | 443.7 | Silur | | 488.3 | Ordovician | | 542 | Cambrian | | 4570 | Precambrian |
◄ Nowadays◄ Cretaceous-Paleogene extinction◄ Triassic extinction◄ Mass Permian Extinction◄ Devonian extinction◄ Ordovician-Silurian extinction◄ Cambrian explosion |
|---|
|
Content
Teleosaurs (old drawing of
1894 )
It is often noted that the teleosaurus was a kind of “ gavial of the prehistoric era” because of its long thin jaws dotted with very sharp small teeth . These jaws were ideally suited for grabbing fish from the water, as their thin shape made it possible to reduce external resistance when opening and closing during swimming, and sometimes increasing the speed of their opening. Moreover, his teeth perfectly performed the function of capturing fish [1] (as well as the squid , which he also probably ate [2] [3] ), since they formed a real “trap” during adhesion [3] . Moreover, due to the small area of their surface, they allowed the jaws to exert very high pressure on the victim’s body (the same principle as, for example, when we point with a pin: the smaller the pressing surface, the greater the pressure exerted). After the teleosaurus managed to grab the fish, he probably somehow twisted it in his mouth until the moment when it takes a convenient position for swallowing. Probably the reason for this was as follows: if the teeth, as already mentioned, were well adapted for fishing, they were not strong enough to tear prey to pieces, and therefore the diet of the teleosaurus was probably very limited - not all fish he could swallow whole [1] .
Teleosaurus fossil at the Cappellini Museum,
Bologna The streamlined body of the teleosaurus suggests that he spent a lot of time in the water, actively hunting and chasing schools of fish. However, his body was not as developed as that of marine crocodilomorphs such as metriorinch and geosaurus , which had a crescent-shaped caudal fin like that of fish. This, in turn, indicates that the teleosaurus may have inhabited coastal waters and spent some time outside the marine environment, perhaps even atolls and lagoons . And besides, such a way of life could allow the teleosaur to survive better in conditions of fierce competition with other fish-eating marine reptiles, such as ichthyosaurs and plesiosaurs , which were widespread in the Jurassic era, but were better adapted to life on the high seas [1] .
Figures of teleosaurs exhibited in the
Crystal Palace A teleosaurus swam, serpentinely bending its graceful body and long tail from side to side, while its short paws, on which there were no membranes, pressed snugly against the body [3] . And the front legs of this creature were two times shorter than the hind legs. The total body length was 3 meters [4] .
The remains of a teleosaurus exhibited at the Geological Museum of
Copenhagen This genus was described by paleontologist Etienne Geoffrey Saint-Hilaire in 1825 . This animal lived in the era of the early Jurassic period, according to some sources, over a period of time approximately 203-175 million years ago. The remains of this animal are found mainly in Europe , in France [4] [3] .
This genus includes the following species:
- T. cadomensis - first described by the French zoologist and algologist Jean Lamourou , assigned to the genus Teleosaurus in 2012 (M. Bronzati et al. 2012). Known, in addition to the holotype (possibly lost), according to the copy of MNHN AC 8746 , which is a quarter of the skull . Known finds are 167.7–164.7 million years old [5] .
- T. asthenodeirus - first described by Richard Owen in 1842 , he also belongs to the genus Teleosaurus [6] [7] .
- T. megarhinus (the species name in Greek means "big-nosed") - was first described by a doctor and fossil collector John Hulke , assigned to the genus Teleosaurus by J. B. Delaire. Known for a typical specimen of BMNH 43086, a partially preserved skull found in Kimmeridge Bay , United Kingdom , in mudstone deposits [8] .