Teleosauridae is a family of extinct typically marine crocodylomorphs similar to the modern gharial that lived during the Jurassic period. Teleosaurids were thalattosuchians closely related to the fully aquatic metriorhynchoids, but were less adapted to an open-ocean, pelagic lifestyle. The family was originally coined to include all the semi-aquatic (i.e. non-metriorhynchoid) thalattosuchians and was equivalent to the modern superfamily Teleosauroidea. However, as teleosauroid relationships and diversity was better studied in the 21st century, the division of teleosauroids into two distinct evolutionary lineages led to the establishment of Teleosauridae as a more restrictive family within the group, together with its sister family Machimosauridae.

Amongst teleosauroids, teleosaurids were generally smaller and less common than machimosaurids, suggesting the two families occupied different niches, similar to modern species of crocodilians. However, teleosaurids were more diverse than machimosaurids, with generalist coastal predators (Mystriosaurus), long-snouted marine piscivores (Bathysuchus), and potentially even long-snouted, semi-terrestrial predators (Teleosaurus). Additionally, teleosaurids occupied a wider range of habitats than machimosaurids, from semi-marine coasts and estuaries, the open-ocean, freshwater, and potentially even semi-terrestrial environments.

Classification

Teleosauridae is phylogenetically defined in the PhyloCode by Mark T. Young and colleagues as "the largest clade within Teleosauroidea containing Teleosaurus cadomensis but not Machimosaurus hugii. Teleosauridae is split into two subfamilies, the Teleosaurinae and the Aeolodontini, the former defined in the PhyloCode as "the largest clade within Teleosauroidea containing Teleosaurus cadomensis, but not Aeolodon priscus and the latter defined in the PhyloCode as "the largest clade within Teleosauroidea containing Aeolodon pricus, but not Steneosaurus megistorhynchus (the genus Seldsienean) and Teleosaurus cadomensis.

ThalattosuchiaMetriorhynchoidea Teleosauroidea Plagiophthalmosuchus Machimosauridae Teleosauridae Indosinosuchus kalasinensis Chinese teleosauroid Mystriosaurus Indosinosuchus potamosiamensis Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
Metriorhynchoidea
TeleosauroideaPlagiophthalmosuchus Machimosauridae Teleosauridae Indosinosuchus kalasinensis Chinese teleosauroid Mystriosaurus Indosinosuchus potamosiamensis Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
Plagiophthalmosuchus
Machimosauridae Teleosauridae Indosinosuchus kalasinensis Chinese teleosauroid Mystriosaurus Indosinosuchus potamosiamensis Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
Machimosauridae
TeleosauridaeIndosinosuchus kalasinensis Chinese teleosauroid Mystriosaurus Indosinosuchus potamosiamensis Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
Indosinosuchus kalasinensis
Chinese teleosauroid Mystriosaurus Indosinosuchus potamosiamensis Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
Chinese teleosauroid Mystriosaurus
Chinese teleosauroid
Mystriosaurus
Indosinosuchus potamosiamensis Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
Indosinosuchus potamosiamensis
Teleosaurinae Teleosaurus Platysuchus Aeolodontinae Mycterosuchus Aeolodon Sericodon Bathysuchus
TeleosaurinaeTeleosaurus Platysuchus
Teleosaurus
Platysuchus
AeolodontinaeMycterosuchus Aeolodon Sericodon Bathysuchus
Mycterosuchus
Aeolodon Sericodon Bathysuchus
Aeolodon
Sericodon Bathysuchus
Sericodon
Bathysuchus

In 2024, Mark Young and colleagues recovered the genus Seldsienean as a teleosaurid and as the sister taxon to the tribe Aeolodontini. They suggested that this clade should be one of the main subfamilies of Teleosauridae, although they left this clade unnamed.

TeleosauroideaMachimosauridae Teleosauridae Mystriosaurus laurillardi Indosinosuchus potamosiamensis Chinese teleosauroid (IVPP V 10098) Teleosaurinae Platysuchus multiscrobiculatus Teleosaurus cadomensis "Unnamed clade" Seldsienean megistorhynchus Aeolodontini Mycterosuchus nasutus Aeolodon priscus Sericodon jugleri Bathysuchus megarhinus
Machimosauridae
TeleosauridaeMystriosaurus laurillardi Indosinosuchus potamosiamensis Chinese teleosauroid (IVPP V 10098) Teleosaurinae Platysuchus multiscrobiculatus Teleosaurus cadomensis "Unnamed clade" Seldsienean megistorhynchus Aeolodontini Mycterosuchus nasutus Aeolodon priscus Sericodon jugleri Bathysuchus megarhinus
Mystriosaurus laurillardi Indosinosuchus potamosiamensis Chinese teleosauroid (IVPP V 10098)
Mystriosaurus laurillardi
Indosinosuchus potamosiamensis Chinese teleosauroid (IVPP V 10098)
Indosinosuchus potamosiamensis
Chinese teleosauroid (IVPP V 10098)
Teleosaurinae Platysuchus multiscrobiculatus Teleosaurus cadomensis "Unnamed clade" Seldsienean megistorhynchus Aeolodontini Mycterosuchus nasutus Aeolodon priscus Sericodon jugleri Bathysuchus megarhinus
TeleosaurinaePlatysuchus multiscrobiculatus Teleosaurus cadomensis
Platysuchus multiscrobiculatus
Teleosaurus cadomensis
"Unnamed clade"Seldsienean megistorhynchus Aeolodontini Mycterosuchus nasutus Aeolodon priscus Sericodon jugleri Bathysuchus megarhinus
Seldsienean megistorhynchus
AeolodontiniMycterosuchus nasutus Aeolodon priscus Sericodon jugleri Bathysuchus megarhinus
Mycterosuchus nasutus
Aeolodon priscus Sericodon jugleri Bathysuchus megarhinus
Aeolodon priscus
Sericodon jugleri Bathysuchus megarhinus
Sericodon jugleri
Bathysuchus megarhinus

Palaeobiology

Teleosaurids were originally regarded as marine analogues to modern gharials, as they both typically share long, tubular snouts and narrow teeth. However, differences in the jaws, teeth, and skeleton of different teleosaurids suggest that they were more ecologically diverse than this. Earlier teleosaurids were coastal semi-aquatic generalists, while the two subfamilies were more specialised. Teleosaurines appear to have been semi-terrestrial, as they were more heavily armoured and had forward-facing nostrils. In contrast, aeolodontines have been found in deep marine waters and had reduced armour, implying that they were open water predators similar to metriorhynchoids (although the oldest aeolodontine, Mycterosuchus, appears to have been semi-terrestrial, similar to teleosaurines).

Palaeoecology

Distribution

Definitive fossils of teleosaurids are restricted to Laurasia, with material found in Europe(England, France, Germany, Italy, Portugal, Russia and Switzerland) and Asia (China and Thailand, and possibly India).

See also