Moeritherium Temporal range: Late Eocene, | |
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M. trigodon skull cast, at the AMNH. | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Proboscidea |
Family: | † Moeritheriidae C.W. Andrews, 1906 |
Genus: | † Moeritherium C.W. Andrews, 1901 |
Type species | |
Moeritherium lyonsi Andrews, 1901 | |
Species | |
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Moeritherium ("the beast from Lake Moeris") is an extinct genus of basal proboscideans from the Eocene of North and West Africa. It was related to elephants and, more distantly, to sea cows and hyraxes.
Moeritherium was a rotund semi-aquatic mammal with short, stubby legs that lived about 37–35 million years ago. [1] Its body shape and lifestyle demonstrate convergent evolution with pigs, tapirs, and the pygmy hippopotamus. Moeritherium was smaller than most or all later proboscideans, standing only 70 centimetres (2.3 ft) high at the shoulder and weighing 235 kilograms (518 lb). [2]
The shape of the skull suggests that, while Moeritherium did not have an elephant-like trunk, it may have had a broad flexible upper lip like a tapir's for grasping aquatic vegetation. The second incisor teeth formed small tusks, although these would have looked more like the teeth of a hippo than a modern elephant. [3] [4]
Isotopic analysis suggests that Moertherium was amphibious/semiaquatic and probably consumed freshwater plants. [5]
In 1901, Charles William Andrews described Moeritherium lyonsi from fossil remains found in the Qasr el Sagha Formation in the Al Fayyum in Egypt. Andrews described Moeritherium gracile from fossil remains of a smaller specimen found in the same area in 1902 in a fluvio-marine formation, [6] [7] that is a river estuary wetlands to brackish lagoon paleoenvironment. In 1904, the first Moeritherium trigodon fossils were discovered by Charles Andrews in the deposits of an oasis in Al Fayyum. [1] [8] It is also found in other sites around North and West Africa. [9]
In 1911, Max Schlosser of Munich divided Moeritherium lyonsi into two species: Moeritherium lyonsi, a large form from the Qasr-el-Sagha formation, and a new large species M. andrewsi from a fluvio-marine formation. [6] [7] [10] In 2006, Moeritherium chehbeurameuri has been described from fossil remains found in the early late Eocene locality of Bir El Ater, Algeria. [11]
Moeritherium is not thought to be directly ancestral to modern elephants; it was a branch of Proboscidea that died out, leaving no descendants. There were several species of other basal proboscideans in existence during the Eocene, and some, such as Phiomia and Palaeomastodon , looked comparatively more like modern elephants. However, Moeritherium was clearly a side branch of the proboscidean family tree, having evolved to resemble other rotund semiaquatic mammals such as pigs, tapirs, and hippos instead of having the typical proboscidean body form. [12]
Proboscidea is a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. First described by J. Illiger in 1811, it encompasses the elephants and their close relatives. Three species of elephant are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant.
A mastodon is a member of the genus Mammut, which, strictly defined, was endemic to North America and lived from the late Miocene to the early Holocene. Mastodons belong to the order Proboscidea, the same order as elephants and mammoths. Mammut is the type genus of the extinct family Mammutidae, which diverged from the ancestors of modern elephants at least 27–25 million years ago, during the Oligocene.
Deinotheriidae is a family of prehistoric elephant-like proboscideans that lived during the Cenozoic era, first appearing in Africa, then spreading across South Asia (Indo-Pakistan) and Europe. During that time, they changed very little, apart from growing much larger in size; by the late Miocene, they had become the largest land animals of their time. Their most distinctive features were their lack of upper tusks and downward-curving tusks on the lower jaw.
Prodeinotherium is an extinct representative of the family Deinotheriidae that lived in Africa, Europe, and Asia in the early and middle Miocene. Prodeinotherium, meaning "before terrible beast", was first named in 1930, but soon after, the only species in it, P. hungaricum, was reassigned to Deinotherium. During the 1970s, however, the two genera were once again separated, with Prodeinotherium diagnosed to include Deinotherium bavaricum, Deinotherium hobleyi, and Deinotherium pentapotamiae, which were separated based on geographic location. The three species are from Europe, Africa, and Asia, respectively. However, because of usage of few characters to separate them, only one species, P. bavaricum, or many more species, including P. cuvieri, P. orlovii, and P. sinense may be possible.
Wādī al-Ḥītān is a paleontological site in the Faiyum Governorate of Egypt, some 150 kilometres (93 mi) south-west of Cairo. It was designated a UNESCO World Heritage Site in July 2005 for its hundreds of fossils of some of the earliest forms of whale, the archaeoceti. The site reveals evidence for the explanation of one of the greatest mysteries of the evolution of whales: the emergence of the whale as an ocean-going mammal from a previous life as a land-based animal.
Phiomia is an extinct genus of basal elephantiform proboscidean that lived in what is now Northern Africa during the Late Eocene to Early Oligocene some 37–30 million years ago. "Phiomia serridens" means "saw-toothed animal of Faiyum".
Numidotheriidae is an extinct family of primitive proboscideans that lived from the late Paleocene to the early Oligocene periods of North Africa.
Numidotherium is an extinct genus of early proboscideans, discovered in 1984, that lived during the middle Eocene of North Africa some 46 million years ago. It was about 90–100 cm (35–39 in) tall at the shoulder and weighed about 250–300 kg (550–660 lb).
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.
Barytherium is a genus of an extinct family (Barytheriidae) of primitive proboscideans that lived during the late Eocene and early Oligocene in North Africa. The type species is Barytherium grave, found at the beginning of the 20th century in Fayum, Egypt. Since then, more complete specimens have been found at Dor el Talha, Libya. More fossils were also discovered in 2011 in the Aidum area in Dhofar by Oman's Ministry of Heritage and Culture, which was named Barytherium omansi.
Palaeomastodon is an extinct genus within the elephant order Proboscidea. Its fossils have been extracted from Oligocene strata conventionally dated to 33.9-23.03 million years old. Usually considered an ancestor or near-ancestor of elephants or mastodons as a member of Elephantiformes it lived in marshes and fluvial-deltaic environments of what is now Egypt, Ethiopia, Libya, and Saudi Arabia.
Eogavialis is an extinct genus of eusuchian crocodylomorph, usually regarded as a gavialoid crocodylian. It superficially resembles Tomistoma schlegelii, the extant false gharial, and consequently material from the genus was originally referred to Tomistoma. Indeed, it was not until 1982 that the name Eogavialis was constructed after it was realised that the specimens were from a more basal form.
The Jebel Qatrani Formation is a geologic formation located in the Faiyum Governorate of central Egypt. It is exposed between the Jebel Qatrani escarpment and the Qasr el Sagha escarpment, north of Birket Qarun lake near Faiyum. The formation conformably overlies the Qasr el Sagha Formation and is topped by the Widan el Faras Basalt. The age of the formation has been subject to debate, but the most recent research indicates that it covers both the latest parts of the Eocene and the Early Oligocene, spanning over the boundary between these two time periods.
The Qasr el Sagha Formation is a geological formation located in Egypt. The formation is part of the Wadi El Hitan World Heritage Site. The Qasr el Sagha Formation overlies the Birket Qarun Formation and is overlain by the Gebel Qatrani Formation. The sandstones and shales of the formation were deposited in a deltaic to shallow marine environment. It dates to the Late Eocene.
Egypt has many fossil-bearing geologic formations, in which many dinosaurs have been discovered.
Saghacetus is an extinct genus of basilosaurid early whale, fossils of which have been found in the Upper Eocene Qasr el Sagha Formation, Egypt.
Apterodon is an extinct genus of hyaenodontid mammals that lived from the late Eocene through the middle Oligocene epoch in Africa and Europe. It is closely related to the African Quasiapterodon, and together it, they comprise the hyainailurids subfamily Apterodontinae.
Saloumia is an extinct genus of the order Proboscidea. It is one of the oldest members of the order and lived in the middle Eocene of Senegal. It is known only from a single molar, whose pronounced bumpy chewing surface indicates it is probably closely related to Moeritherium.
Dagbatitherium is an extinct genus of proboscideans. So far a single molar from the phosphate basins of Togo in West Africa has been found. The fossil dates to the Middle Eocene, around 47 million years ago. A striking feature of the tooth are the three pairs of cusps oriented transversely to the longitudinal axis of the tooth. This feature is found in more derived proboscideans, which are grouped in the Elephantiformes. For its age, Dagbatitherium is the earliest member of Elephantiformes to date. Furthermore, it is characterized by a low tooth crown and a humped occlusal pattern. The genus was described in 2021.
The Fayyum is a region and an important fossil Lagerstätte in northern Egypt. The region comprises the Fayyum Basin, which is intensively used for agriculture, and adjoining areas; the important areas of discovery are mostly north and west of Lake Qarun. The Wadi al-Hitan, known for its numerous whale fossils and since 2005 UNESCO World Natural Heritage Site, forms the south-western end. The deposits of the Fayyum belong to various geological formations. They are mainly composed of limestone, siltstone and sandstone. The lower sections consist of marine sediments, while the upper, continental sediments were formed in a coastal landscape. The formation period ranges from the Middle to the Upper Eocene to the Lower Oligocene, which corresponds to an age of around 41 to 28 million years ago. The entire sedimentary complex is overlain by basalt, which dates back to volcanic activity around 24 million years ago.