Talattosuchia had a very long muzzle, in which the upper jaws are connected by a middle suture. The nasal bones are short, the posterior temporal foramen is wide, a small preorbital window is preserved, which sometimes, however, can be lost. The postorbital arch is located beneath the skin, superficially. The pitted sculpture of the bones of the skull, which is characteristic of mesosuchia and eusuchia , is weakly expressed in talatozuhi. The base of the skull and pterygoids are located horizontally. The retroarticular process is long. The limbs, especially the front ones, are shortened. Early positioning of the talatosuchi from other crocodilomorphs is indicated by the above-described position and structure of the preorbital window, the postorbital arch and the posterior temporal opening [1] .
According to Fraas, this suborder belonged only to the specialized, unsanctioned "marine crocodiles" of the Metriorhynchidae family, but the cladistic analysis carried out by Clark in 1986 showed their affinity with the more primitive armored marine crocodilomorphs of the Teleosauridae family. Nevertheless, the families of talantozuchi differ significantly from each other, which raises doubts about the genetic unity of the group [1] .
Teleosaurids
The family of teleosaurids (Teleosauridae), less adapted to marine life, lived in coastal seas, were dressed in a shell: on the back - from overgrown paramedian plates, on the belly - from mosaics separated by seams of relatively small bone plates. Teleosaurids swam with the help of tail movements, shortened forelimbs were not converted to flippers. The muzzle was greatly lengthened, as in modern gavials , possibly due to the feeding of relative small prey in the water [2] .
More than 10 genera of teleosaurids are known, mainly from the Jurassic of Western Europe, but the most common genus Steneosaurus was also found in the lower Jurassic of South America and Madagascar, and the genus Machimosaurus is also indicated for the Lower Cretaceous of Western Europe. The endocranium casting of Steneosaurus reflects their great similarity in the shape of the brain to modern crocodiles, but the large width of the intracranial veins is probably associated with difficulties in cerebral circulation when diving.
Teleosaurids usually reached a length of 3-4 m, but in the Early Cretaceous Machimosaurus, the total length reached 7.15 m [3] . This crocodilomorph was also distinguished by flattened cheek teeth. In the “multi-tooth” genus Teleosaurus, the total number of teeth in the jaws reached 200 [1] .
Metriorhinids
Old reconstruction of the marine crocodilomorph
Geosaurus The Metriorhynchid family [1] (Metriorhynchidae) is the most specialized marine crocodilomorph that has completely lost its shell, with the exception of the Early Jurassic Pelagisaurus , which preserved its remains; obviously, this animal was a connecting link between metriorhinchids and teleosaurs. The neck is somewhat shortened - by 1-2 segments in comparison with modern crocodiles; the tail, as in ichthyosaurs , is reverse heterocercal , with a bend in the last quarter; forelegs are pinnate, with a strongly shortened forearm. The posterior spine is bent ventrally to support the large caudal fin, the total number of pre-sacral vertebrae increases to 26. Of the cranial bones, the sculpture is well expressed only on the frontal bone, the preorbital window is usually lost. Metriorinchids are smaller than teleosaurids, their length usually does not exceed 1.5-2.5 m. Although, the largest representatives, adapted for active hunting of large animals, grew to more than 6.7 meters ( plesiosuchus ). The geographical distribution of metriorinchids and changes in their diversity depending on temperature and sea level indicates a high level of metabolism and, possibly, warm-blooded representatives of this group [4] .
No more than 10 genera of metriorinchids are described. Only Pelagisaurus originates from the Lower Jurassic, while the remaining metriorhinchids are known only from the Middle and Upper Jurassic and Lower Cretaceous. Outside Western Europe, only Purranisaurus and Geosaurus from the upper Jurassic of Argentina were discovered [1] [2] .
