"Crocodylus" gariepensis

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"Crocodylus" gariepensis
Temporal range: Early Miocene, 17.5  Ma
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Scientific classification
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"C." gariepensis
Binomial name
†"Crocodylus" gariepensis
Pickford, 2003

"Crocodylus" gariepensis is an extinct species of crocodile that lived in southern Africa during the Early Miocene [1] about 17.5 million years ago (Ma). [2] Fossils have been found along a bank of the Orange River in Namibia, near its border with South Africa. [1]

Contents

Classification and Phylogeny

When the species was named in 2003, [3] it was hypothesized to be ancestral to the living Nile crocodile, Crocodylus niloticus . During this time the fossil record of C. niloticus was thought to extend back into the Late Miocene, meaning that "C." gariepensis could have been a direct precursor to the species. [4] More recent studies propose that C. niloticus first appeared much more recently, making "C." gariepensis an unlikely ancestor of the Nile crocodile. Moreover, the most recent phylogenetic studies of crocodiles place "C." gariepensis in an evolutionary position outside other living species of Crocodylus , far from the position of C. niloticus. Indeed, the species appears to be an osteolaemine more closely related to dwarf crocodiles ( Osteolaemus ) and possibly slender-snouted crocodiles ( Mecistops ), as shown in the cladogram below: [5]

Crocodylidae
Osteolaeminae

Rimasuchus lloydi

Voay robustus

Osteolaemus osborni Osborn’s dwarf crocodile

Osteolaemus tetraspis Dwarf crocodile

"Crocodylus" gariepensis

Brochuchus parvidens

Brochuchus pigotti

Euthecodon arambourgi

Euthecodon brumpti

Crocodylinae

Mecistops cataphractus West African slender-snouted crocodile

Crocodylus thorbjarnarsoni

Crocodylus anthropophagus

Crocodylus niloticus Nile crocodile

Crocodylus checchiai

Crocodylus moreletii Morelet's crocodile

Crocodylus intermedius Orinoco crocodile

Crocodylus acutus American crocodile

Crocodylus rhombifer Cuban crocodile

Crocodylus palaeindicus

Crocodylus palustris Mugger crocodile

Crocodylus ossifragus

Crocodylus siamensis Siamese crocodile

Crocodylus mindorensis Philippine crocodile

Crocodylus johnstoni Freshwater crocodile

Crocodylus porosus Saltwater crocodile

Crocodylus raninus Borneo crocodile

Crocodylus novaeguineae New Guinea crocodile  

Paleoafrican Crocodylus
Neotropical Crocodylus
Indo-Pacific Crocodylus

Paleoecology

Although much of Namibia is currently arid, "C." gariepensis lived during a time when the local climate was humid and subtropical. It likely inhabited gallery forests surrounding the Orange River. Fossils of giant tortoises and a variety of small burrowing mammals have been found in the same deposits. [2]

Related Research Articles

<span class="mw-page-title-main">Crocodylinae</span> Subfamily of crocodiles

Crocodylinae is a subfamily of true crocodiles within the family Crocodylidae, and is the sister taxon to Osteolaeminae.

<i>Crocodylus</i> Genus of reptiles

Crocodylus is a genus of true crocodiles in the family Crocodylidae.

<i>Mecistops</i> Genus of reptiles

Mecistops is a genus of crocodiles, the slender-snouted crocodiles, native to sub-Saharan Africa.

<span class="mw-page-title-main">Sicilian shrew</span> Species of mammal

The Sicilian shrew is a species of mammal in the family Soricidae. It is found in Sicily (Italy) and Gozo (Malta). Its natural habitat is temperate shrubland.

<i>Euthecodon</i> Extinct genus of crocodilian

Euthecodon is an extinct genus of long-snouted crocodile. It was common throughout much of Africa during the Neogene, with fossils being especially common in Kenya, Ethiopia, and Libya. Although superficially resembling that of gharials, the long snout was a trait developed independently from that of other crocodilians and suggests a diet of primarily fish. Euthecodon coexisted with a wide range of other crocodiles in the areas it inhabited before eventually going extinct during the Pleistocene.

Eosaurichthys is an extinct genus of saurichthyid ray-finned fish that lived during the late Permian epoch in what is now China.

<i>Voay</i> Extinct genus of reptiles

Voay is an extinct genus of crocodile from Madagascar that lived during the Late Pleistocene to Holocene, containing only one species, V. robustus. Numerous subfossils have been found, including complete skulls, noted for their distinctive pair of horns on the posterior, as well as vertebrae and osteoderms from such places as Ambolisatra and Antsirabe. The genus is thought to have become extinct relatively recently. It has been suggested to have disappeared in the extinction event that wiped out much of the endemic megafauna on Madagascar, such as the elephant bird and Malagasy hippo, following the arrival of humans to Madagascar around 2000 years ago. Its name comes from the Malagasy word for crocodile.

<i>Hippotherium</i> Extinct genus of mammals

Hippotherium is an extinct genus of horse that lived in during the Miocene through Pliocene ~13.65—6.7 Mya, existing for 6.95 million years.

<i>Crocodylus anthropophagus</i> Extinct species of reptile

Crocodylus anthropophagus is an extinct species of crocodile from the Pleistocene of Tanzania. It lived 1.84 million years ago. It was a large-sized predator reaching a length of 7.5 m (25 ft).

<i>Sinosaurichthys</i> Extinct genus of fishes

Sinosaurichthys is an extinct genus of saurichthyid ray-finned fish, which existed in southwestern China during the Middle Triassic. Fossils have been found in the Upper Member of the Guanling Formation of two localities: Yangjuan of Panxian County, Guizhou Province, and Dawazi of Luoping, Yunnan Province, China.

<span class="mw-page-title-main">Saurichthyiformes</span> Extinct order of fishes

Saurichthyiformes is an extinct order of ray-finned fish which existed in Asia, Africa, Australia, Europe and North America, during the late Permian to early Middle Jurassic. Saurichthyiiformes comprise two families, Saurichthyidae and Yelangichthyidae. Yelangichthyidae is monotypic, containing only the genus Yelangichthys. The gar or needlefish-like Saurichthyidae is primarily known from the genus Saurichthys. Additionally, the subgenera SaurorhynchusCostasaurichthys, Eosaurichthys, Lepidosaurichthys, and Sinosaurichthys are frequently used to group species, and are sometimes considered separate genera. Species are known from both marine end freshwater deposits. They had their highest diversity during the Early and Middle Triassic. Their phylogenetic position is uncertain, while they have often been considered members of Chondrostei, and thus related to living sturgeons and paddlefish, phylogenetic analysis of well-preserved remains has considered this relationship equivocal. They may actually belong to the stem-group of Actinopterygii, and thus not closely related to any living group of ray-finned fish.

Rimasuchus is an extinct genus of crocodile from the Miocene of Egypt and possibly Libya. Only one species - Rimasuchus lloydi - is currently known. It was previously thought to be a species of Crocodylus, but is now thought to be more closely related to the modern African dwarf crocodiles (Osteolaemus).

<span class="mw-page-title-main">Osteolaeminae</span> Subfamily of crocodiles

Osteolaeminae is a subfamily of true crocodiles within the family Crocodylidae containing the dwarf crocodiles and slender-snouted crocodiles, and is the sister taxon to Crocodylinae.

<i>Crocodylus thorbjarnarsoni</i> Species of extinct reptile

Crocodylus thorbjarnarsoni is an extinct species of crocodile from the Pliocene and Pleistocene of the Turkana Basin in Kenya. It is closely related to the species Crocodylus anthropophagus, which lived during the same time in Tanzania. C. thorbjarnarsoni could be the largest known true crocodile, with the largest skull found indicating a possible total length up to 7.6 m (25 ft). It may have been a predator of early hominins. Crocodylus thorbjarnarsoni was named by Christopher Brochu and Glenn Storrs in 2012 in honor of John Thorbjarnarson, a conservationist who worked to protect endangered crocodilians.

<i>Crocodylus checchiai</i> Extinct species of reptile

Crocodylus checchiai is an extinct species of crocodile from the Miocene to Pliocene of Libya and Kenya. C. checchiai was named in 1947 based on a skull from the Sahabi Formation. Remains from the lower Nawata Formation in the Turkana Basin of Kenya that were first attributed to the Nile crocodile have now been reassigned to C. checchiai, extending its geographic range. The morphology of the species, in particular the pronounced rostral boss, indicates that it may be the connecting link between African and American species of the genus Crocodylus.

<span class="mw-page-title-main">Narrow-nosed rhinoceros</span> Extinct species of rhinoceros

The narrow-nosed rhinoceros, also known as the steppe rhinoceros is an extinct species of rhinoceros belonging to the genus Stephanorhinus that lived in western Eurasia, including Europe, as well as North Africa during the Pleistocene. It first appeared in Europe some 600,000 years ago during the Middle Pleistocene and survived there until as recently as 40,000 years before present.

<i>Crocodylus falconensis</i> Extinct species of reptile

Crocodylus falconensis is an extinct species of crocodile known from the early Pliocene of the lower part of the Vergel Member of the San Gregorio Formation of Venezuela. C. falconensis was named in 2013 after Falcón State and is thought to be the basalmost species of Crocodylus found in the Neotropics.

Plesiocetus is a genus of extinct balaenopterids found worldwide. It has had a chequered taxonomic history, having served as a wastebasket genus for a handful of mysticete species.

Rhagapodemus is a genus of extinct rodent from the Miocene to Pleistocene periods. Most species are known from European localities, although R. debruijni comes from India.

Buya or Buia is an archaeological site in the Danakil Depression of Eritrea. It is known for the discovery of Madam Buya, a one million-year-old fossil of a Homo erectus skull. Two other expeditions in 2011 and 2012 also unearthed ancient hominid fossils at the site. Archaeologists have uncovered large quantities of animal fossils and lithic tools in the area.

References

  1. 1 2 Brochu, C. A.; Storrs, G. W. (2012). "A giant crocodile from the Plio-Pleistocene of Kenya, the phylogenetic relationships of Neogene African crocodylines, and the antiquity of Crocodylus in Africa". Journal of Vertebrate Paleontology. 32 (3): 587–602. doi:10.1080/02724634.2012.652324. S2CID   85103427.
  2. 1 2 Senut, B.; Pickford, M.; Ségalen, L. C. (2009). "Neogene desertification of Africa". Comptes Rendus Geoscience. 341 (8–9): 591–602. Bibcode:2009CRGeo.341..591S. doi:10.1016/j.crte.2009.03.008.
  3. Pickford, M. (2003). "A new species of crocodile from Early and Middle Miocene deposits of the Lower Orange River Valley, Namibia, and the origins of the Nile crocodile (Crocodylus niloticus)" (PDF). Memoirs of the Geological Survey of Namibia. 19: 51–65.
  4. Delfino, M.; Segid, A.; Yosief, D.; Shoshani, J.; Rook, L.; Libsekal, Y. (2004). "Fossil reptiles from the Pleistocene Homo-bearing locality of Buia (Eritrea, Northern Danakil Depression)". Rivista Italiana di Paleontologia e Stratigrafia. 110 (Suppl): 51–60. doi:10.13130/2039-4942/5764.
  5. Azarra, Beatrice; Boschian, Giovanni; Brochu, Christopher; Delfino, Massimo; Iurino, Dawid Adam; Kimambo, Jackson Stanley; Manzi, Giorgio; Masao, Fidelis T.; Menconero, Sofia; Njau, Jackson K; Cherin, Marco (2021). "A new cranium of Crocodylus anthropophagus from Olduvai Gorge, northern Tanzania". Rivista Italiana di Paleontologia e Stratigrafia (Research in Paleontology and Stratigraphy). 127 (2): 275–295. doi:10.13130/2039-4942/15771.