قالب وردپرس درنا توس
Home / Science / Miocene minerals from Africa provide new data on the origin of American crocodiles Paleontology

Miocene minerals from Africa provide new data on the origin of American crocodiles Paleontology



A team of paleontologists from Italy and Spain compared the only well-preserved skull in Russia Crocodylus checchiai– an extinct species of crocodile that lived in present-day Libya about 7 million years ago (Miocene era), among the four living species of crocodiles from America and found that the ancient African reptile is closely related to American crocodiles. The findings suggest that crocodiles may migrate from Africa to America during the Miocene.

Life of Crocodylus checchiai from Al-Sahabi, Libya.  Image credit: DA Iurino

Lifestyle Crocodylus checchiai from Sahabi, Libya. Image credit: DA Iurino

The skull and associated lower jaw of an adult Crocodylus checchiai were collected in 1938 at the paleontological site of Al-Sahabi in northern Libya.

The specimen was described in 1947 by the Italian paleontologist Angiola Maria Maccagno and then placed in the collections of the Istituto di Paleontologia dell’Università di Roma.

In order to improve knowledge about Crocodylus checchiai and his possible relationship with American crocodiles, Dr. Massimo Delfino of the University of Turin and the University of Barcelona and his colleagues tried to find the original Crocodylus checchiai skull.

Researchers have found it in the collection of the University Museum of Earth Sciences at the University of Rome Sapienza.

They then used computed tomography (CT) to re-examine the well-preserved sample.

The 7 millionth skull of Crocodylus checchiai from Al-Sahabi, Libya, in dorsal (a1, a2), ventral (b1, b2), right lateral (c1, c2) and left lateral (d1, d2) views.  Anatomical abbreviations: bo - basiocytic, bs - basisphenoid, ect - ectopterygoid, en - external threaded, f - frontal, if - incision, itf - intra-abdominal fenestra, j - egg, l - lacrimal, m - maxillary, n - nasal, o - orbit, pa - parietal, pal - palatine, pf - prefrontal, pm - premaxilla, po - postorbital, pt - pterygoid, q - square, qj - quadrilateral, soc - epigastric, soft - suborbital fenestra, sq - skamosal, stf - supratemporal fenestra, t - tooth.  Scale scale - 10 cm.  Credit graphics: Delfino et al, doi: 10.1038 / s41598-020-68482-5.

7 million skull with Crocodylus checchiai from the Sahaba, Libya, in the dorsal (a1, a2), ventral (b1, b2), right lateral (c1, c2) and left lateral (d1, d2) species. Anatomical abbreviations: bo – basiocytic, bs – basisphenoid, ect – ectopterygoid, en – external threaded, f – frontal, if – incision, itf – intra-abdominal fenestra, j – egg, l – lacrimal, m – maxillary, n – nasal, o – orbit, pa – parietal, pal – palatine, pf – prefrontal, pm – premaxilla, po – postorbital, pt – pterygoid, q – square, qj – quadrilateral, soc – epigastric, soft – suborbital fenestra, sq – skamosal, stf – supratemporal fenestra, t – tooth. Scale scale – 10 cm. Credit image: Delfino etc, doi: 10.1038 / s41598-020-68482-5.

They identified several new internal structures, including protrusions in the middle of the snout, which were not detected by any other species of African crocodiles.

This unique structure, called the boss of the middle rostral, is also present in four living American species of crocodiles: Crocodylus intermedius,, C. moreletii, C. acutus and C. rhombifer, and indicates a close evolutionary relationship between Crocodylus checchiai and crocodiles from America.

“Analysis of the evolutionary relationships between species allows us to do this Crocodylus checchiai may be part of the same line as four American crocodiles, scientists said.

“Remains of Crocodylus checchiai they were dated about 7 million years ago, while the oldest remains of an American crocodile, extinct Crocodylus falconensis, were dated about 5 million years ago. “

“Based on these findings, we suggest that crocodiles reach America by migrating west from Australia to Africa.”

The results were published in the journal Scientific reports.

_____

M. Delfino etc. 2020. Old African fossils provide new evidence for the origin of American crocodiles. Scientific rap 10, 11127; doi: 10.1038 / s41598-020-68482-5


Source link