Miocorvus
Miocorvus larteti, Skeletal reconstruction of Alphonse Milne -Edwards
- Sansan (France)
Miocorvus larteti is an extinct species of corvids ( Corvidae ). She is the only member of the genus Miocorvus and lived in the middle Miocene in Europe. Miocorvus larteti was a medium-sized Corvide, reaching about the size of falco - jays. The known finds are all from the south of France fossil deposit Sansan, where the time of occurrence of Miocorvus larteti existed a freshwater marsh in humid climates. There the kind likely moving in the branches of riparian forests.
Miocorvus larteti was described in 1871 by Alphonse Milne -Edwards and placed in a separate genus later Kálmán Lambrecht. The remains found so far include fossil leg, shoulder and wing bones. The species is the oldest known bird raven with an age of around 15 million years ago.
Features
Miocorvus larteti was, judging by the leg and wing bones, a medium-sized and rather petite raven bird. He was slightly smaller than the living today jay (Garrulus glanduarius ). The humerus was compared to the ravens and crows (Corvus ) strong, the attachment points of the flight feathers ( ulnar papillae ) were more developed. Osteologically similar Miocorvus larteti several extant genera of the Corvidae. Comparisons with several European genera showed in the skeletal features in common with blue magpies ( Cyanopica ), skipjack magpies ( Pica ), but especially with the jays of the genus falco. Miocorvus differs from these, however, especially in the construction of the tarsometatarsus, whose sharp edge is less developed and has a recessed socket as Cyanopica.
Sites and fossil material
Miocorvus larteti has so far been found only in the fossil deposit Sansan in southern France. In more northerly deposits of a similar age, such as Peter book or in Ries, lacks the Art The previously salvaged fossil material of the type derived from at least 21 individuals and includes bones from the running and flying machine and the shoulder girdle.
Habitat
While the existence of Miocorvus larteti was on the Fund Location Sansan a wetland with a subtropical microclimate. Along a river system grew alluvial forests with the hackberry Celtis lacunosa and the nutmeg plant Myristicacarpum miocaenicum, water lily plants and Chara were found. As in Sansan more copies of Miocorvus larteti were found than from any other species of bird, it is assumed that open, moist forests were part of the typical habitat of the species. His habitat Miocorvus shared with crocodiles turtles and representatives of the Miocene mammal fauna, such as the giraffe Eotragus sansaniensis and the deer Dicrocerus elegans. Other birds that were found in the location site of Sansan, gallinaceous birds, herons and parrots, as well as birds of prey, such as from the genus Accipiter are (Accipiter ).
Temporal classification
Fossils of Miocorvus have so far been found only in the zone MN 6 Sansan in deeper horizons lack the Art Fund With an age of about 15.0 to 15.2 million years ago is the oldest known Miocorvus representative of the family of corvids. Other fossil corvids appear until some time later with Miopica paradoxa in the upper Miocene of Ukraine and Miocitta galbreathi from the upper Miocene of Colorado.
Systematics and Taxonomy
The first bone fragment of Miocorvus - the lower part of a run- bone - was found mid-19th century by Édouard Armand Lartet, who discovered the fossil site Sansan. The first description was in 1871 by Alphonse Milne -Edwards in the second volume of his Recherches et Anatomiques Paléontologiques. Milne -Edwards manufactured to drawings of the available bone material as well as a skeletal reconstruction and gave the type the name Corvus larteti, when he saw a strong resemblance to living today ravens and crows. As an epithet he chose to honor larteti Lartets.
A first cursory review of the species description Milne -Edwards ' took Kálmán Lambrecht 1933. In his Palaeoornithologie he agreed to the assignment of the species to the corvids in principle, but took the view that the specific nature of the bones and their old age to justify a separate genus. He chose as a new genus name Miocorax, where he made a mistake: he had already used in an earlier passage of the work for a fossil species of cormorants the same name, so it could not be used according to the rules of zoological nomenclature again. Lambrecht noticed this error only after the pressure of the core text and corrected the name later in a footnote of Miocorax to Miocorvus. The name is made up of million - for Miocene and Latin corvus for " Raven".
An extensive revision of Miocorvus remained out for a long time, even if it was as required by Pierce Brodkorb. In 2000, Jacques Cheneval Miocorvus larteti underwent close scrutiny. He measured and compared bone material of the individuals found so far with each other and with respect to the family assignment came to the same conclusion as Milne -Edwards. As lectotype he adopted a slightly damaged tarsometatarsus ( MNHN SA 1248 ), from which he believed that he was shown in the original drawings of Milne -Edwards. As he paralectotypes certain other bones of Milne -Edwards ' original material. Jirí Mlíkovský disagreed with the choice of lectotype by pointing out to Milne -Edwards ' panels are several different bone to see only the same type are. Although warned Mlíkovský to further investigation of Miocorvus, the assignment of fossils to the corvids valid, however, largely for granted.