Crocodylus palaeindicus

Crocodylus palaeindicus is an extinct species of crocodile from southern Asia. C. palaeindicus lived from the Miocene to the Pliocene. It may be an ancestor of the living Mugger crocodile.

Crocodylus palaeindicus Temporal range: Late Miocene–Pliocene,
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	Archosauromorpha
Clade:	Archosauriformes
Order:	Crocodilia
Family:	Crocodylidae
Genus:	Crocodylus
Species:	†C. palaeindicus
Binomial name
†Crocodylus palaeindicus Falconer, 1859
Synonyms
Crocodylus sivalensis Lydekker, 1886

History

C. palaeindicus was first named by Scottish paleontologist Hugh Falconer in 1859. Falconer found fossils of the species in the Siwalik Hills of India along with the remains of many other animals like turtles, ostriches, camels, saber-toothed cats, mastodons. Richard Lydekker later named another crocodile from the Siwalik Hills which he called C. sivalensis. Although the two crocodiles are very similar, C. sivalensis was distinguished from C. palaeindicus because the margin of its skull was less convex. C. sivalensis has recently been synonymized with C. palaeindicus, as the slight differences in shape are thought to be from natural variation or from fossilization. In later years, fossils were also found from Pakistan and Myanmar.

Classification

The Mugger crocodile, a close relative and possible descendant of Crocodylus palaeindicus

Historically, C. palaeindicus was considered a direct ancestor of the Mugger crocodile C. palustris. The two species are similar in appearance, and some fossils of C. palaeindicus were at first mistaken for C. palustris. Most modern phylogenetic analyses of crocodiles place C. palaeindicus in a basal position among members of the genus Crocodylus. Below is a cladogram modified from Brochu et al. (2010) showing the relation of C. palaeindicus with other crocodiles:

Crocodylidae

Tomistominae  Crocodylinae  †Mekosuchinae †"Crocodylus" megarhinus Osteolaeminae Mecistops cataphractus Crocodylus niloticus  New World crocodiles Crocodylus acutus Crocodylus intermedius Crocodylus rhombifer Crocodylus moreletii †Crocodylus anthropophagus †Crocodylus palaeindicus Crocodylus palustris  Indopacific crocodiles Crocodylus siamensis Crocodylus porosus Crocodylus johnstoni Crocodylus novaeguineae Crocodylus mindorensis

A 2018 tip dating study by Lee & Yates simultaneously using morphological, molecular (DNA sequencing), and stratigraphic (fossil age) data established the inter-relationships within Crocodylidae. In 2021, Hekkala et al. were able to use paleogenomics, extracting DNA from the extinct Voay, to better establish the relationships within Crocodylidae, including the subfamilies Crocodylinae and Osteolaeminae.

The below cladogram shows the results of the latest study:

Crocodylidae

Osteolaeminae Mecistops cataphractus West African slender-snouted crocodile Euthecodon† Brochuchus† Rimasuchus† Osteolaemus osborni Osborn’s dwarf crocodile Osteolaemus tetraspis Dwarf crocodile Crocodylinae Voay† Crocodylus Crocodylus anthropophagus† Crocodylus thorbjarnarsoni† Crocodylus palaeindicus† Crocodylus Tirari Desert† Asia+Australia Crocodylus johnstoni Freshwater crocodile Crocodylus novaeguineae New Guinea crocodile Crocodylus mindorensis Philippine crocodile Crocodylus porosus Saltwater crocodile Crocodylus siamensis Siamese crocodile Crocodylus palustris Mugger crocodile Africa+New World Crocodylus checchiai† Crocodylus falconensis† Crocodylus suchus West African crocodile Crocodylus niloticus Nile crocodile New World Crocodylus moreletii Morelet's crocodile Crocodylus rhombifer Cuban crocodile Crocodylus intermedius Orinoco crocodile Crocodylus acutus American crocodile

(crown group)