Dinnebitodon
Encyclopedia
Dinnebitodon was an advanced herbivorous
cynodont
of the early Jurassic
period. It has only been found in the Kayenta Formation
in northeastern Arizona. It closely resembles the related genus Kayentatherium
from the same formation. It is set apart by differences in the dentition, while resembling in most other respects.
family. The description of Dinnebitodon does not give details on the structure of the body other than to say it was similar to Kayentatherium.
surfaces. The teeth are notably different from the other two named Kayenta tritylodonts, Kayentatherium and Oligokyphus
.
was deposited in an environment of braided rivers and dune fields, similar to northern Senegal
today. Dinnebitodon was a terrestrial animal, living in the "Silty Facies" of the Kayenta Formation, which would have represented a interdunal river deposit. The teeth resemble those of modern animals that also feed on seeds and nuts, suggesting that perhaps Dinnebitodon fed on similar foods present during the early Jurassic Period. Considering it was living alongside its close relative Kayentatherium, some niche partitioning of the resources would have been necessary in order to avoid being outcompeted for a food source. This might explain why two similar looking animals have different dentition.
.
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
cynodont
Cynodont
Cynodontia or cynodonts are a taxon of therapsids which first appeared in the Late Permian and were eventually distributed throughout all seven continents by the Early Triassic . This clade includes modern mammals and their extinct close relatives. They were one of the most diverse groups of...
of the early Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
period. It has only been found in the Kayenta Formation
Kayenta Formation
The Kayenta Formation is a geologic layer in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. This rock formation is particularly prominent in southeastern Utah, where it is seen in the...
in northeastern Arizona. It closely resembles the related genus Kayentatherium
Kayentatherium
Kayentatherium is a genus of tritylodont, historically referred to as "mammal-like" reptiles. It is one of three tritylodonts from the Kayenta Formation of northern Arizona, United States.-Description:...
from the same formation. It is set apart by differences in the dentition, while resembling in most other respects.
Description
Dinnebitodon (meaning "Dinnebito (Wash) tooth"), was a small quadrupedal animal, with a head 8 centimetres (3.1 in) in length, belonging to the herbivorous TritylodontidaeTritylodontidae
Tritylodontids were small to medium-sized, highly specialized and extremely mammal-like cynodonts. They were the last family of the non-mammalian synapsids. One of the last cynodont lines to appear, the Tritylodontidae descended from a Cynognathus-like cynodont...
family. The description of Dinnebitodon does not give details on the structure of the body other than to say it was similar to Kayentatherium.
Skull and jaw
The majority of the remains so far recovered and assigned to the genus Dinnebitodon are skull and jaw material. These show that Dinnebitodon had a skull 8 centimetres (3.1 in) long and unique in form. There are three incisors on each side of the upper jaw, with the second incisor being large and well developed at 9 millimetre (0.354330708661417 in) by 7 millimetre (0.275590551181102 in). There are five postcanine teeth in the upper jaw that would have been functional when Dinnebitodon was alive, with a sixth possibly erupting later in the animal's life. The postcanine teeth resemble rounded-off squares with three rows of cusps on their occlusalOcclusion (dentistry)
Occlusion, in a dental context, means simply the contact between teeth. More technically, it is the relationship between the maxillary and mandibular teeth when they approach each other, as occurs during chewing or at rest....
surfaces. The teeth are notably different from the other two named Kayenta tritylodonts, Kayentatherium and Oligokyphus
Oligokyphus
Oligokyphus was an advanced herbivorous cynodont of the late Triassic to early Jurassic periods. Originally considered to be an early mammal, it is now classified as a synapsid because Oligokyphus does not have the mammalian jaw attachments and it retains a vestigial joint between the quadrate...
.
Habitat
The Kayenta FormationKayenta Formation
The Kayenta Formation is a geologic layer in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. This rock formation is particularly prominent in southeastern Utah, where it is seen in the...
was deposited in an environment of braided rivers and dune fields, similar to northern Senegal
Senegal
Senegal , officially the Republic of Senegal , is a country in western Africa. It owes its name to the Sénégal River that borders it to the east and north...
today. Dinnebitodon was a terrestrial animal, living in the "Silty Facies" of the Kayenta Formation, which would have represented a interdunal river deposit. The teeth resemble those of modern animals that also feed on seeds and nuts, suggesting that perhaps Dinnebitodon fed on similar foods present during the early Jurassic Period. Considering it was living alongside its close relative Kayentatherium, some niche partitioning of the resources would have been necessary in order to avoid being outcompeted for a food source. This might explain why two similar looking animals have different dentition.
Fossil finds
Dinnebitodon fossils were first discovered by William Amaral (for whom the species is named) in 1978 Remains of Dinnebitodon are housed at Harvard's Museum of Comparative Zoology and at the Museum of Northern ArizonaMuseum of Northern Arizona
The Museum of Northern Arizona is a museum in Flagstaff, Arizona, USA, that was established as a repository for Native American artifacts and natural history specimens from the Colorado Plateau.The museum was founded in 1928 by zoologist Dr. Harold S...
.
See also
- Kayenta FormationKayenta FormationThe Kayenta Formation is a geologic layer in the Glen Canyon Group that is spread across the Colorado Plateau province of the United States, including northern Arizona, northwest Colorado, Nevada, and Utah. This rock formation is particularly prominent in southeastern Utah, where it is seen in the...
- OligokyphusOligokyphusOligokyphus was an advanced herbivorous cynodont of the late Triassic to early Jurassic periods. Originally considered to be an early mammal, it is now classified as a synapsid because Oligokyphus does not have the mammalian jaw attachments and it retains a vestigial joint between the quadrate...
- KayentatheriumKayentatheriumKayentatherium is a genus of tritylodont, historically referred to as "mammal-like" reptiles. It is one of three tritylodonts from the Kayenta Formation of northern Arizona, United States.-Description:...