Abdounodus

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Abdounodus
Temporal range: Paleocene 61–59  Ma
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Abdounodus hamdii left dentary.jpg
A. hamdii lower jaw
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Superorder: Afrotheria
Clade: Paenungulatomorpha
Genus: Abdounodus
Gheerbrant & Sudre, 2001
Species:
A. hamdii
Binomial name
Abdounodus hamdii
Gheerbrant et al., 2001

Abdounodus ("Abdoun tooth") is an extinct genus of mammal known from the middle Paleocene of Northern Africa. The sole species, A. hamdii, is known from teeth and jaw bones discovered in the Ouled Abdoun Basin of present-day Morocco in 2001. [1] [2]

Contents

Discovery and naming

Discovery

The holotype of Abdounodus hamdii MNHN 21 was collected in French fossil markets. [1] It consists of a left mandible and teeth. A study in 2016 described new material that included the maxillary and upper dentition. [2]

Naming

The generic name combines Abdoun referring to the place of origin and odus meaning tooth. The specific name hamdii is named after M. Mohamed Hamdi, who was an active supporter for paleontological research in the region. [2]

Description

Abdounotus has dentition similar of that mioclaenids, but is differentiated by features such as the talonid being short and narrow, the posfossid being weakly excavated, the entoconid being quite large, lack of cingula, and a small and a inflated hypocounlid. [1] The upper molars are noticeably bunodont with an inflated crown and bulbous cusps, and have 3 roots. There also features that support a meatconule-dervived pseudohypocone such as a absence of other conules aside from the metaconule-pseudohypocone. [2]

Classification

In a study in 2016 it was classified as a basal afrothere It was hypothesized that Abdounodus and Ocepeia are transitional lophodont stem paenugulates. In the same study the authors erected a new clade called Paenungulatomorpha. [2]

Hadrogeneios

Paleobiology

Diet

Abdounodus would’ve likely ate hard and abrasive plants as its jaw and tooth  remains show it would’ve likely had a strong crushing motion. [2]

Related Research Articles

<span class="mw-page-title-main">Dentition</span> Development and arrangement of teeth

Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology of the teeth of an animal.

<span class="mw-page-title-main">Mesonychia</span> Extinct taxon of carnivorous ungulates

Mesonychia is an extinct taxon of small- to large-sized carnivorous ungulates related to artiodactyls. Mesonychians first appeared in the early Paleocene, went into a sharp decline at the end of the Eocene, and died out entirely when the last genus, Mongolestes, became extinct in the early Oligocene. In Asia, the record of their history suggests they grew gradually larger and more predatory over time, then shifted to scavenging and bone-crushing lifestyles before the group became extinct.

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

Daouitherium is an extinct genus of early proboscideans that lived during the early Eocene some 55 million years ago in North Africa.

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

Phosphatherium escuillei is a basal proboscidean that lived from the Late Paleocene to the early stages of the Ypresian age. Research has suggested that Phosphatherium existed during the Eocene period.

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

Didymictis is an extinct genus of placental mammals from extinct subfamily Didymictinae within extinct family Viverravidae, that lived in North America and Europe from the late Paleocene to middle Eocene.

Argochampsa is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodilian, related to modern gharials. It lived in the Paleocene of Morocco. Described by Hua and Jouve in 2004, the type species is A. krebsi, with the species named for Bernard Krebs. Argochampsa had a long narrow snout, and appears to have been marine in habits.

<span class="mw-page-title-main">Tillodontia</span> Extinct suborder of mammals

Tillodontia is an extinct suborder of eutherian mammals known from the Early Paleocene to Late Eocene of China, the Late Paleocene to Middle Eocene of North America where they display their maximum species diversity, the Middle Eocene of Pakistan, and the Early Eocene of Europe. Leaving no descendants, they are most closely related to the pantodonts, another extinct group. The tillodonts were medium- to large-sized animals that probably fed on roots and tubers in temperate to subtropical habitats.

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

Eritherium is an extinct genus of early Proboscidea found in the Ouled Abdoun basin, Morocco. It lived about 60 million years ago. It was first named by Emmanuel Gheerbrant in 2009 and the type species is Eritherium azzouzorum. Eritherium is the oldest, smallest and most primitive known elephant relative.

Eremiasaurus is a genus of mosasaurs, an extinct group of marine reptiles. It lived during the Maastrichtian stage of the Late Cretaceous in what is now North Africa. Only one species is known, E. heterodontus, described in 2012 from two remarkably complete fossil specimens discovered in the Ouled Abdoun Basin, Morocco. This site is known to have delivered a significant number of other related mosasaurs.

<i>Ocepeia</i> Extinct Afrotherian mammal

Ocepeia is an extinct genus of afrotherian mammal that lived in present-day Morocco during the middle Paleocene epoch, approximately 60 million years ago. First named and described in 2001, the type species is O. daouiensis from the Selandian stage of Morocco's Ouled Abdoun Basin. A second, larger species, O. grandis, is known from the Thanetian, a slightly younger stage in the same area. In life, the two species are estimated to have weighed about 3.5 kg (7.7 lb) and 10 kg (22 lb), respectively, and are believed to have been specialized leaf-eaters. The fossil skulls of Ocepeia are the oldest known afrotherian skulls, and the best-known of any Paleocene mammal in Africa.

<span class="mw-page-title-main">Ouled Abdoun Basin</span> Phosphate basin in Morocco

The Oulad Abdoun Basin is a phosphate sedimentary basin located in Morocco, near the city of Khouribga. It is the largest in Morocco, comprising 44% of Morocco's phosphate reserves, and at least 26.8 billion tons of phosphate. It is also known as an important site for vertebrate fossils, with deposits ranging from the Late Cretaceous (Cenomanian-Turonian) to the Eocene epoch (Ypresian), a period of about 25 million years.

<i>Chenanisaurus</i> Extinct genus of dinosaurs

Chenanisaurus is a genus of predatory abelisaurid dinosaur, with a single known species C. barbaricus. It comes from the upper Maastrichtian phosphates of the Ouled Abdoun Basin in Morocco, North Africa. The animal is known from a holotype, consisting of a partial jaw bone, and several isolated teeth found in the same beds. Chenanisaurus is one of the largest members of the Abelisauridae, and one of the last, being a contemporary of the North American Tyrannosaurus. It would have been among the dinosaur species wiped out by the Chicxulub asteroid impact and the Cretaceous-Paleogene mass extinction that followed.

Azygonyx was a small tillodont mammal, likely the size of a cat to raccoon, that lived in North America during the Paleocene and Eocene in the early part of the Cenozoic Era. The only fossils that have been recovered are from the Willwood and Fort Union Formations in the Bighorn Basin of Wyoming, United States, and date to the Clarkforkian to Wasatchian, about 56 to 50 million years ago. Fifty-six collections that have been recovered thus far include the remains of Azygonyx. Azygonyx survived the Paleocene Eocene Thermal Maximum along with other mammals like Phenacodus and Ectocion, both of which were ground-dwelling mammals. Azygonyx probably was a generalist terrestrial mammal that may have roamed around the ground, but was also capable of climbing trees.

Carpodaptes was a genus that encompassed small, insectivorous animals that roamed the Earth during the Late Paleocene. Specifically, Carpodaptes can be found between the Tiffanian and Clarkforkian periods of North America. Although little evidence, this genus may have made it through to the early Eocene. They are known primarily from collections of jaw and teeth fragments in North America, mainly in southwestern Canada and northwestern America. Carpodaptes are estimated to have weighed approximately 53-96 grams which made them a little bigger than a mouse. However small, Carpodaptes was a placental mammal within the order Plesiadapiformes that appeared to have a high fiber diet. This insect-eating mammal may have been one of the first to evolve fingernails in place of claws. This may have helped them pick insects, nuts, and seeds more easily off the ground than with paws or claws. Carpodaptes was thought to only exist in North America but recent discoveries of dentition fragments have been found in China.

<i>Xenodens</i> Extinct genus of lizards

Xenodens is an extinct genus of marine lizard belonging to the mosasaur family. It currently contains a single species, X. calminechari, which is known from Late Maastrichtian phosphate deposits in the Ouled Abdoun Basin, Morocco. Its closest known relative is believed to be the durophagous Carinodens.

Azilestes is a genus of probable zhelestid eutherian mammal, a family consisting of small herbivores, that was discovered in the early Maastrichtian Grès de Labarre Formation of France. It is a monotypic genus, with only type species A. ragei being known. Only one specimen, the holotype described in 2021, is known. It consists of a partial dentary with teeth.

<i>Thalassotitan</i> Large bodied African mosasaur

Thalassotitan is an extinct genus of large mosasaurs that lived during the late Maastrichtian of the Cretaceous period in what is now Morocco, around 67 to 66 million years ago. The only known species is T. atrox, described in 2022 from fossils discovered in the Ouled Abdoun Basin, initially identified as coming from other genera such as Mosasaurus or Prognathodon. Hypothetical Thalassotitan specimens may have been found in other corners of the world, although researchers also note the possibility that they come from distinct, related taxa. It is considered to be close to the genera Prognathodon and Gnathomortis, together forming the tribe Prognathodontini. The prognathodontines are separated from other mosasaurs based on their massive jaws and robust teeth.

Hadrogeneios is an extinct genus of afrotherian mammal recovered from the Khouribga Phosphates of the Ouled Abdoun Basin dating from the Selandian to the Thanetian. Only the type species H. phosphaticus is known for this genus, with the material being of dental and jaw specimens. The placement of Hadrogeneios recovered it to be the most basal stem-paenungulate, the clade that includes elephants, sea cows, and hyraxes. Despite this Hadrogeneios was a contemporary of more derived members of the group such as Abdounodus, Ocepeia, and the early proboscideans Eritherium, Phosphatherium, and Daouitherium.

<span class="mw-page-title-main">Paenungulatomorpha</span> Clade of mammals

Paenungulatomorpha is a clade of afrotherian mammals that can be characterized according to Gheerbrant et al. (2016):

by a mandibular retromolar fossa, the absence of hypocone, an ectoloph selenodont and linked to strong styles such as mesostyle in basal taxa, and a more or less developed pseudohypocone.

Grand Daoui is a quarry in the Ouled Abdoun Basin of Morocco known for its fossils. It is the discovery place of Phosphatherium escuilliei, the earliest known proboscidean. It was the location for several field parties between 1997 and 2001, which allowed survey of the geological and paleontological context of Phosphatherium localities. It is also rich in marine vertebrae fossils. All Phosphatherium remains to date have been found in the quarry. The discovery of fossils there has aided in the study of early African placental fauna. The marine snake Palaeophis maghrebianus is also known from the locality, as well as the primitive gavialoid Argochampsa krebsi.

References

  1. 1 2 3 Gheerbrant, Emmanuel; Sudre, Jean; Iarochene, Mohamed; Moumni, Abdelkader (2001). "First ascertained African "Condylarth" mammals (primitive ungulates: cf. Bulbulodentata and cf. Phenacodonta) from the earliest Ypresian of the Ouled Abdoun Basin, Morocco". Journal of Vertebrate Paleontology. 21 (1): 107–118. doi:10.1671/0272-4634(2001)021[0107:FAACMP]2.0.CO;2. JSTOR   4524176. S2CID   85966740.
  2. 1 2 3 4 5 6 Gheerbrant, Emmanuel; Filippo, Andrea; Schmitt, Arnaud (2016). "Convergence of Afrotherian and Laurasiatherian Ungulate-Like Mammals: First Morphological Evidence from the Paleocene of Morocco". PLOS ONE. 11 (7): e0157556. Bibcode:2016PLoSO..1157556G. doi: 10.1371/journal.pone.0157556 . PMC   4934866 . PMID   27384169.