Daouitherium
Lower jaw of Daouitherium rebouli
- Daouitherium rebouli
Daouitherium a genus formerly Russell animals. It lived in the transition from the Paleocene to Eocene of 59-51 million years ago in North Africa. The previously discovered fossils belong to a not fully grown individual, due to the size of the collection is assumed that a body weight of 80 to 170 kg.
Features
Daouitherium is only known from a few jaw fragments and isolated molars of an immature animal. The longest fragment represents a left pine bough having a length of 12 cm and a height of the body to the bone 5 cm. The more damaged right pine bough has additionally the joint approach. The anterior dentition is not fossil- handed, however, proved by the existing four alveoli. They each have a small distance to each other, so that the front set of teeth was probably not closed. The foremost alveolus is quite large and indicates that Daouitherium also had a prolonged first incisor ( I1). The other tooth chambers are difficult to assign, since juveniles partly have a different structure than adult teeth animals, the researchers assume, however, that this tooth chambers are assigned to the other two incisors and the canine.
The posterior dentition includes the last three premolars and three molars, the first premolar was probably reduced, as with other early proboscidean, about Phosphatherium and Numidotherium. The premolars are slightly molarisiert with an enamel bar on the Kauoberfläche, the last to approach a second bar bears ( semibilophodont ). The molars are significantly bilophodont, their size increases backwards too strong. The last molar has a third bar approaches. Overall, the molars are niederkronig ( brachyodont ).
System
Daouitherium part due to the bilophodonten front molars to the original Plesielephantiformes and is adjacent Eritherium and Phosphatherium one of the oldest known representatives of the Proboscidea. A further indication of the very original position, the existing vertical change of teeth with a simultaneous use of all teeth; typical for today's elephants horizontal change of teeth did not develop until later. Its clearly lophodonten teeth provide Daouitherium closer to Phosphatherium and Numidotherium, and it probably took a kind of intermediate position. An archaic feature over Numidotherium is the lack of diastema between front and rear dentition, opposite Phosphatherium the much larger body shape is much more modern. A direct assignment to the family Numidotheriidae was previously only with question marks. Significant differences exist at the somewhat later forms Arcanotherium and Moeritherium whose molars were designed rather bunolophodont and so were the later proboscidean closer.
Discovery history
The finds were discovered in the northeast area of the Ouled Abdoun Basin - section Sidi Daoui ( Grand Daoui ) in Morocco. The local phosphate mines generally include layers of Thanetium (late Paleocene ) and lowest Ypresium (early Eocene ) and are known for their rich fossil record. With Eritherium and Phosphatherium two very early mammoths were discovered here also. Were found the remains of Daouitherium by locals in Sidi Daoui. Roland Reboul, an amateur paleontologist who finds purchased from a fossil dealers. The holotype ( specimen number CPSGM MA4 ) is a left mandibular arch with preserved dentition of the last two premolars and molars all dar. He is now preserved in the paleontological collection of the Office Chérifien des Phosphates ( OCP). The genus name refers to a Daouitherium to the reference in Sidi Daoui, on the other hand is θηρίον ( Therion ), the Greek word for " animal ". The species name honors the rebouli Finder Ronald Reboul, who presented the findings available to scientists.