Buxolestes Temporal range: Middle Eocene ~ | |
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Buxolestes minor from Messel Pit Fossil Site at the Naturmuseum Senckenberg | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | † Cimolesta |
Family: | † Pantolestidae |
Subfamily: | † Pantolestinae |
Genus: | † Buxolestes Jaeger, 1970 |
Buxolestes is an extinct genus of semi-aquatic, non-placental eutherian mammals belonging to the family Pantolestidae. Species in this genus were part of the first placental evolutionary radiation during the Middle Eocene (48-40 mya) and found in the Bracklesham Group and Wittering Formation of England, at the Messel Pit in Germany and in Bouxwiller, France.
Buxolestes were otter-like freshwater fish predators with a body length reaching about 46 centimetres (18 in) and a tail about 35 centimetres (14 in) long. They were significantly smaller than most living species of otters. Fossilized stomach contents confirm their semiaquatic freshwater habits. The anatomy of these archaic "insectivorous" mammals is known through well-preserved Middle Eocene specimens found at Messel in Germany. Their structure evidences a clear adaptation to a semiaquatic way of life. The forelimbs and hindlimbs are powerful and show strong claws. The tail is clearly fit for swimming. The skull is long, with large molars that appear to be adapted to a diet of molluscs with shells (freshwater clams and freshwater snails), but the predilection postulated from the dentition has not been confirmed.
A tenrec is a mammal belonging to any species within the afrotherian family Tenrecidae, which is endemic to Madagascar. Tenrecs are a very diverse group; as a result of convergent evolution, some resemble hedgehogs, shrews, opossums, rats, and mice. They occupy aquatic, arboreal, terrestrial, and fossorial environments. Some of these species, including the greater hedgehog tenrec, can be found in the Madagascar dry deciduous forests. However, the speciation rate in this group has been higher in humid forests.
A dormouse is a rodent of the family Gliridae. Dormice are nocturnal animals found in Africa, Asia, and Europe. They are named for their long, dormant hibernation period of six months or longer.
Leptictidium is an extinct genus of small mammals that were likely bipedal. Comprising eight species, they resembled today's bilbies, bandicoots, and elephant shrews, and occupied a similar niche. They are especially interesting for their combination of characteristics typical of primitive eutherians with highly specialized adaptations, such as powerful hind legs and a long tail which aided in locomotion. They were omnivorous, their diet a combination of insects, lizards, frogs, and small mammals. Leptictidium and other leptictids are not placentals, but are non-placental eutherians, although they are closely related to placental eutherians. They appeared in the Lower Eocene, a time of warm temperatures and high humidity, roughly fifty million years ago. Although they were widespread throughout Europe, they became extinct around thirty-five million years ago with no descendants, as they were adapted to live in forest ecosystems and were unable to adapt to the open plains of the Oligocene.
Moeritherium 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.
The Messel pit is a disused quarry near the village of Messel about 35 km (22 mi) southeast of Frankfurt am Main, Germany. Bituminous shale was mined there. Because of its abundance of well-preserved fossils of the Messel Formation dating from the middle of the Eocene, it has significant geological and scientific importance. Over 1000 species of plants and animals have been found at the site. After almost becoming a landfill, strong local resistance eventually stopped these plans and the Messel pit was declared a UNESCO World Heritage Site on 9 December 1995. Significant scientific discoveries about the early evolution of mammals and birds are still being made at the Messel pit, and the site has increasingly become a tourist site as well.
Kopidodon is a genus of extinct squirrel-like mammals belonging to the order Cimolesta. Kopidodon was one of the largest tree-dwelling mammals known from Eocene Europe: growing 115 centimeters long. This mammal sported large canine teeth, probably for defense, since its molars were adapted for chewing plants, not flesh. Its legs and claws allowed Kopidodon to scramble through the trees with the greatest of ease, much like modern-day squirrels. Its fossils were found in the Messel pit, preserving even its fur. Kopidodon had a thick bushy tail for balance.
Leptictis is an extinct genus of leptictid non-placental eutherian mammal known from the Late Eocene to Early Oligocene of North America. The type species, L. haydeni, was named in 1868 by Joseph Leidy in honour of Ferdinand Vandeveer Hayden. L. dakotensis was also named by Leidy in 1868, but he originally named it as a separate genus, Ictops, which is now seen as the same animal as Lepticitis. Since then, six other species have been named. The hind limbs are proportionally elongated compared to their forelimbs similar to elephant shrews, though to a lesser degree than Leptictidium, and it is suggested that they were capable of rapid bursts of quadrupedal locomotion, unlike the bipedal locomotion suggested for Leptictidium. The forelimbs were likely used for digging.
Paroodectes is an extinct genus of placental mammals from clade Carnivoraformes, that lived in Europe during the middle Eocene.
Cimolestes is a genus of early eutherians with a full complement of teeth adapted for eating insects and other small animals. Paleontologists have disagreed on its relationship to other mammals, in part because quite different animals were assigned to the genus, making Cimolestes a grade taxon of animals with similar features rather than a genus of closely related ones. Fossils have been found in North America, South America, Europe and Africa. Cimolestes first appeared during the Late Cretaceous of North America. According to some paleontologists, Cimolestes died out at the start of the Paleocene, while others report the genus from the early Eocene.
Ernanodon is an extinct genus of placental mammal from extinct family Ernanodontidae within extinct order Palaeanodonta, that lived from the middle to late Paleocene in China and Mongolia.
Messelogale is an extinct genus of placental mammals from clade Carnivoraformes, that lived in Europe during the middle Eocene.
Leptictida is a possibly paraphyletic extinct order of eutherian mammals. Their classification is contentious: according to cladistic studies, they may be (distantly) related to Euarchontoglires, although they are more recently regarded as the first branch to split from basal eutherians. One recent large-scale cladistic analysis of eutherian mammals favored lepictidans as close to the placental crown-clade; and several other recent analyses that included data from Cretaceous non-eutherian mammals found Leptictis to belong to the superorder Afrotheria.
Macrocranion is a genus of extinct mammal from the Eocene epoch of Europe and North America. Exceptional fossils have has been found in the Messel Pit of Germany. Macrocranion species are often described as forest-floor predators, about the size of small squirrels but with longer limbs. The genus is represented at the Messel Pit site by two species, M. tupaidon and M. tenerum.
Pantolestidae is an extinct family of semi-aquatic, non-placental eutherian mammals. Forming the core of the equally extinct suborder Pantolesta, the pantolestids evolved as a series of increasingly otter-like forms, ranging from the Middle Paleocene Bessoecetor to the Late Eocene (Ergilian) Gobiopithecus and Kiinkerishella. They first appear in North America, whence they spread to Europe.
Titanomyrma is a genus of extinct giant ants which lived during the Eocene. The type species Titanomyrma gigantea and the smaller Titanomyrma simillima are known from the Eocene of Germany, while the third species Titanomyrma lubei, is known from Wyoming, United States. The presence of Titanomyrma in North America was considered to indicate "the first reported cross-Arctic dispersal by a thermophilic insect group". However a queen reported from Upland temperate shales in British Columbia raised questions on the exact thermophilic nature of the genus. The type species of this genus, T. gigantea, is the largest-known fossil or extant species of ant in the world.
Lesmesodon is an extinct genus of placental mammals from extinct family Proviverridae within extinct superfamily Hyaenodontoidea, that lived during the Early to Middle Eocene. It was found in France and in the Messel Pit in Germany. Lesmesodon was a weasel-sized carnivorous mammal.
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.
Geiseltaliellus is an extinct genus of iguanian lizards that lived in what is now western Europe during the Eocene. It belongs to the family Corytophanidae, which includes modern casquehead lizards. Many fossils are known from Germany, France, and Belgium, with the most well preserved coming from the Messel pit lagerstätte in Messel, Germany. German paleontologist Oskar Kuhn named the genus in 1944 after the Geiseltal valley where the first specimens were found, designating the type species Geiseltaliellus longicaudus. Three new species — G. louisi, G. lamandini, and G. grisolli — were named in the 1990s and 2000s on the basis of more fragmentary remains from France and Belgium, although G. louisi has since been synonymized with G. longicaudus. In 2009 the Messel pit specimens were recognized as belonging to a species distinct from that of the G. longicaudus specimens in Geiseltalt and were collectively reclassified under a new name, G. maarius.
Colombitherium is an extinct mammal from Late Eocene Colombia. It has originally been assigned to the order Pyrotheria and the family Colombitheriidae, although a later detailed analysis of the fossil questions that classification. A fossil jawbone of approximately 9 centimetres (3.5 in) length of Colombitherium has been found by Texas Petroleum in 1945, in the Upper Eocene strata of the middle Gualanday Group in the department of Tolima, Central Ranges of the Colombian Andes.
Apatemys is a member of the family Apatemyidae, an extinct group of small and insectivorous placental mammals that lived in the Paleogene of North America, India, and Europe. While the number of genera and species is less agreed upon, it has been determined that two apatemyid genera, Apatemys and Sinclairella, existed sequentially during the Eocene in North America. The genus Apatemys, living as far back as 50.3 million years ago (mya), existed through part of the Wasatchian and persisted through the Duchesnean, and Sinclairella followed, existing from the Duchesnean through the Arikareean. Examinations of specimens belonging to the genus Apatemys suggest adaptations characteristic of arboreal mammals.