Haramiyida

• Western Europe, Greenland, Tanzania, China

The Haramiyida are a group of extinct mammals that are covered only by sparse tooth and jaw finds and lived in the Triassic and Jurassic age.

General

The oldest finds are from the Upper Triassic, they are around 210 million years old and are in addition to Adelobasileus cromptoni the oldest known mammal fossils. The recent finds of this group are dated to the Upper Jurassic. The previously discovered fossils consist mainly of remains of the jaw and teeth, remains have been found in Europe, Greenland, Africa and China.

The knowledge about these animals is mainly limited to the facts derivable from the teeth. The jaw teeth are provided with a number of relatively large bumps and, more precisely three major one on the side, and five small, on the other side of the tooth. Between the cusps there was a depression in which the cusps of opposing teeth into it added.

The relationships of the Haramiyida to other groups of mammals are still unclear, they are usually considered to be very original side branch. Because of the similarities in the structure of the teeth Haramiyida of a once widespread, distributed by the Jurassic to the Eocene mammal group, which is also characterized by numerous bumps on the back teeth were formerly regarded as ancestors of Multituberculata. Haramiyida and Multituberculata were combined in a common taxon, Allotheria. However, the construction of the jaw, has been known since the discoveries of Haramiyavia can even detect very primitive traits. Since the Multituberculata in their Kieferbau showed stronger similarities to today's mammals, it would be a convergent evolution in the evolution of the jaw. The majority of today's scientists regard it as unlikely, so you now rather assumes that the similarities in the structure of teeth are purely external. Most likely probably the Haramiyida represent an isolated early side branch in the evolution of mammals.

The genera

• Individual teeth that were found in various countries of Western Europe from the time of the Upper Triassic and lower Jurassic, were classified in the genus Haramiya and Thomasia. More recent discoveries is evidence that this is merely the upper ( Haramiya ) and lower ( Thomasia ) molars of the same class of priority reasons ( the older name in this case is the valid ) the finds are named in Thomasia ( after Oldfield Thomas, a major mammalian researchers ) classified.
• From Haramiyavia from the Upper Triassic, found in Greenland, the fossils so far the best preserved are known. Besides teeth were found remains of the lower jaw and even individual parts of the rest of the skeleton, which point to a small, agile animal. The skull length of Haramiyavia is estimated to be 4 cm; the dentition suggests a plant or omnivores.
• A single tooth from the Upper Triassic is all that is known of the genus Hypsiprymnopsis.
• From the genus Theroteinus only individual teeth are also known, which come from France and are dated to the Upper Triassic.
• Even Mojo is known only from isolated teeth, which were found in Belgium and also from the Upper Triassic.
• More recently, the genus Eleutherodon, which is known from England and also remains were found in China by the year 2005. She has lived in the Middle Jurassic.
• From two other genera, Millsodon and Kirtlingtonia, individual teeth are also in 2005 in England have been found from the Middle Jurassic.
• The genus Staffia is the geologically youngest representatives of Haramiyida and the first one was discovered in the former Gondwana. Dental finds of this species were made in Tanzania and are dated to the Upper Jurassic.