Palaeontology: Ancient African skull sheds light on American crocodile origins
Scientific Reports
July 24, 2020
The extinct African crocodile species Crocodylus checchiai may be closely related to American crocodile species alive today, according to a study published in Scientific Reports. The findings suggest that crocodiles may have migrated from Africa to America during the Late Miocene epoch (11–5 million years ago).
Prior to this discovery it was unclear whether crocodiles reached the Americas from Africa, via a hypothesized transatlantic voyage, or vice-versa. Massimo Delfino, Dawid Iurino and colleagues used CT imaging to re-examine a skull of C. checchiai that was discovered in 1939 in As Sahabi, Libya and is stored at the Earth Sciences museum (MUST) of Sapienza University of Rome. The authors identified several new skull structures including a protrusion in the middle of the snout of C. checchiai that has not been identified on any other African crocodile species, but that is present on the skulls of the four living American crocodile species: Crocodylus intermedius, C. moreleti, C. acutus and C. rhombifer. This shared skeletal structure indicates a close evolutionary relationship between C. checchiai and American crocodiles.
Further analyses of the evolutionary relationships between species suggest that C. checchiai may be part of the same lineage as the four crocodile species found in North and South America today. The remains of C. checchiai have been dated to around seven million years ago while the oldest remains of an American crocodile, the extinct C. falconensis, have been dated to around five million years ago. Based on these findings, the authors propose that crocodiles reached America by migrating westwards from Australasia via Africa.
doi: 10.1038/s41598-020-68482-5
Research highlights
-
Jun 24
Palaeontology: It sucked to be the prey of ancient cephalopodsScientific Reports
-
Jun 24
Sport science: New wearable sensor to measure neck strain may detect potential concussionScientific Reports
-
Jun 23
Scientific community: Women credited less than men in scientific paper authorshipNature
-
Jun 17
Health technology: New cost-effective smartphone test for middle ear functionCommunications Medicine
-
Jun 17
Conservation: Feral cats pushing critically endangered marsupial further towards extinctionScientific Reports
-
Jun 16
Microbiology: DNA analysis indicates origins of the Black DeathNature