Ronzotherium Temporal range: Late Eocene - Late Oligocene | |
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R. filholi maxilla from the Phosphatiere de Quercy, France, in Musee d'Histoire Naturelle, Paris | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Order: | Perissodactyla |
Family: | Rhinocerotidae |
Genus: | † Ronzotherium Aymard, 1854 |
Type species | |
†Ronzotherium velaunum Lartet, 1851 [1] | |
Species | |
See text |
Ronzotherium is an extinct genus of perissodactyl mammal from the family Rhinocerotidae. The name derives from the hill of 'Ronzon', the French locality near Le Puy-en-Velay at which it was first discovered, and the Greek suffix 'therium' meaning 'beast'. At present 5 species have been identified from several localities in Europe and Asia, spanning the Late Eocene to Upper Oligocene (37 - 23 million years ago).
Ronzotherium was a small to mid-sized rhinocerotid. Smaller species weighed in the region of 1t, while larger species could reach 1.9t in weight. [2] The genus was similar in weight to the extant black rhinoceros although with an overall more slender and gracile build, with a long humerus and femur in comparison to other rhinocerotids. The genus shows a trend for increased size, with later species being considerably larger than some of its first representatives. [3]
Ronzotherium did not possess a nasal horn. Instead the nasal bones were retracted, suggesting the presence of a large prehensile upper lip like those seen in modern rhinoceros species. The lower incisors of Ronzotherium were long and tusk- like, with a large diastema in the lower jaw between the incisors and other teeth. The upper incisors were much smaller. The forelimbs were tetradactyl with a prominent central metapodal. The hindlimbs however were tridactyl, with three toes. [3]
Ronzotherium is a basal genus within the family Rhinocerotidae, one of three families contained within the superfamily Rhinocerotoidea, along with the Hyracodontidae and Amynodontidae. The family also contains all 5 extant rhinoceros species.
5 species have been identified within the genus:
The 3 European species are believed to have dispersed into Europe during the lower Rupelian as part of the Grande Coupure, and were seemingly widespread in the post-grande coupure fauna of Europe, with fossils discovered in Rupelian deposits from the United Kingdom, France, Germany, Italy, Switzerland, and the Czech Republic. Ronzotherium brevirostre and Ronzotheriumorientale are known exclusively from the Late Eocene of Mongolia. Further material has been found in the Linxia basin in China's gansu province. [4]
Isotope analysis of teeth discovered at Rickenbach in Switzerland has shown that european Ronzotherium species were adapted to the increasingly drier climate and open landscapes of the post-grande coupure Oligocene. The low crowned dentition suggests that Ronzotherium was a browser, feeding on the leaves of shrubs, bushes, and small trees. [5] [6] This is supported by the presence of the a prehensile upper lip which is used by modern rhinocerotids to browse on foliage. [3]
The gracile build and long limb bones found in Ronzotherium suggest that it could have been capable of sustained running. [3]
Fossil rhinocerotid trackways assigned to the ichnotaxon Rhinoceripeda voconsense (Vialov 1966) have been discovered at two sites in the Luberon Natural Regional Park in southeast France. The trackways are preserved in the Calcaires de La Fayette, a calcareous lacustrian deposit dating to the lower Rupelian, and are exposed at Saignon and Viens. Various other trackways including artiodactyls and possibly creodonts are also present. Based on the 1974 discovery of a Ronzotherium velaunum mandible in lower Oligocene strata at Viens, the tracks are attributed to Ronzotherium. [7]
In the United Kingdom rare isolated teeth and bone fragments, attributed to Ronzotherium romani, have been found from the Rupelian aged Bouldnor Formation on the Isle Of Wight. Here Ronzotherium formed part of the post-grande coupure fauna alongside anthracotheres, entelodonts, and a variety of other Asian derived groups. [8]
Ronzotherium remains have been recovered from numerous Oligocene sites throughout France. In the Rupelian strata of the Paris Basin material attributed to R.romani has been collected from Etampes and Ferte-Alais. [8] In south-western France the fossiliferous Quercy Phosphorites Formation has produced Ronzotherium material, including an intact maxilla. A large majority of France's Ronzotherium material comes from the Oligocene deposits of the Luberon Massif, northwest of the city of Marseille. Here fossil trackways and bone fragments of Ronzotherium dating from the early Oligocene have been discovered at the villages of Saignon and Viens. [7] Further south at Les Milles bone fragments and a nearly intact mandible have been collected. Finds have also come from the city of Marseille itself. At Saint-Henri and Saint-Andre in the north of the city 50 fragments of bone and dentition have been recovered, including a mandible and semi-intact upper jaw [9]
The Espenhain mines in Saxony have produced a series of Ronzotherium teeth. The locality, south of Leipzig, exposes the Bohn Formation, a predominantly marine sequence of Rupelian age that has preserved a rich terrestrial fauna of post-grande coupure mammals. [10]
Switzerland preserves the oldest, and some of the youngest evidence of the genus in Europe. At Kleinblauen and Bressaucourt in northwest Switzerland the mandible of a juvenile animal, along with other finds, provides the earliest known occurrence of Ronzotherium in Europe. [2] At the late Oligocene locality of Rickenbach 35 fragments of cranial and post-cranial material have been recovered from Chattian strata. [5]
The late eocene Ergilin Dzo Formation in Mongolia has produced the remains of two species of Ronzotherium; R.brevirostre and R.orientale. This is the earliest known occurrence of the genus, dated at 37 million years ago. [11] Further asian finds come from the Late Oligocene of China's Linxia Basin, where an unspecified species of Ronzotherium lived alongside a diversity of other late Paleogene rhinocerotids. [4]
Paraceratherium is an extinct genus of hornless rhinocerotoids belonging to the family Paraceratheriidae. It is one of the largest terrestrial mammals that has ever existed and lived from the early to late Oligocene epoch. The first fossils were discovered in what is now Pakistan, and remains have been found across Eurasia between China and the Balkans. Paraceratherium means "near the hornless beast", in reference to Aceratherium, the genus in which the type species P. bugtiense was originally placed.
Palaeotherium is an extinct genus of equoid that lived in Europe and possibly the Middle East from the Middle Eocene to the Early Oligocene. It is the type genus of the Palaeotheriidae, a group exclusive to the Palaeogene that was closest in relation to the Equidae, which contains horses plus their closest relatives and ancestors. Fossils of Palaeotherium were first described in 1782 by the French naturalist Robert de Lamanon and then closely studied by another French naturalist, Georges Cuvier, after 1798. Cuvier erected the genus in 1804 and recognized multiple species based on overall fossil sizes and forms. As one of the first fossil genera to be recognized with official taxonomic authority, it is recognized as an important milestone within the field of palaeontology. The research by early naturalists on Palaeotherium contributed to the developing ideas of evolution, extinction, and succession and demonstrating the morphological diversity of different species within one genus.
Amphicyon is an extinct genus of large carnivorans belonging to the family Amphicyonidae, subfamily Amphicyoninae, from the Miocene epoch. Members of this family received their vernacular name for possessing bear-like and dog-like features. They ranged over North America, Europe, Asia, and Africa.
Pyrotherium is an extinct genus of South American ungulate, of the order Pyrotheria, that lived in what is now Argentina and Bolivia, during the Late Oligocene. It was named Pyrotherium because the first specimens were excavated from an ancient volcanic ash deposit. Fossils of the genus have been found in the Deseado and Sarmiento Formations of Argentina and the Salla Formation of Bolivia.
Iranotherium is an extinct genus of large elasmotheriine rhinocerotids, comparable in size to a modern white rhino. It is known from the Late Miocene (Tortonian) of Maragha, Iran and the middle part of the Liushu formation of northwestern China. It was a precursor to the related Sinotherium and may have been ultimately outcompeted by its descendant. This species is most well known for showing unique sexual dimorphism among rhinos.
Chilotherium is an extinct genus of rhinocerotids endemic to Eurasia during the Miocene through Pliocene living for 13.7—3.4 mya, existing for approximately 10.3 million years.
Anoplotherium is the type genus of the extinct Palaeogene artiodactyl family Anoplotheriidae, which was endemic to Western Europe. It lived from the late Eocene to the earliest Oligocene. It was the fifth fossil mammal genus to be described with official taxonomic authority, with a history extending back to 1804 when its fossils from Montmartre in Paris, France were first described by the French naturalist Georges Cuvier. Discoveries of incomplete skeletons of A. commune in 1807 led Cuvier to thoroughly describe unusual features for which there are no modern analogues. His drawn skeletal and muscle reconstructions of A. commune in 1812 were amongst the first instances of anatomical reconstructions based on fossil evidence. Cuvier's contributions to palaeontology based on his works on the genus were revolutionary for the field, not only proving the developing ideas of extinction and ecological succession but also paving the way for subfields such as palaeoneurology. Today, there are four known species.
Leontinia is an extinct genus of leontiniid notoungulate. Fossils have been found in the Deseado and Sarmiento Formations in Argentina and Trembembé Formation of Brazil, and are the most abundant remains of any animal found there. The genus dates back to the Late Oligocene, Deseadan in the SALMA classification.
Pterodon is an extinct genus of hyaenodont in the family Hyainailouridae, containing five species. The type species Pterodon dasyuroides is known exclusively from the late Eocene to the earliest Oligocene of western Europe. The genus was first erected by the French zoologist Henri Marie Ducrotay de Blainville in 1839, who said that Georges Cuvier presented one of its fossils to a conference in 1828 but died before he could make a formal description of it. It was the second hyaenodont genus with taxonomic validity after Hyaenodon, but this resulted in taxonomic confusion over the validities of the two genera by other taxonomists. Although the taxonomic status of Pterodon was revised during the late 19th and early 20th centuries, it became a wastebasket taxon for other hyaenodont species found in Africa and Asia. Today, only the type species is recognized as belonging to the genus while four others are pending reassessment to other genera.
Lagrivea is a fossil genus of squirrel from the Middle Miocene of France. The single species, L. vireti, is known from three mandibles and two isolated teeth. All come from the fissure filling of La Grive L5, part of the La Grive-Saint-Alban complex in Saint-Alban-de-Roche, southeastern France. Lagrivea was a large tree squirrel with flat lower incisors and a large, triangular fourth lower premolar (p4). Each of the four cheekteeth bears a deep basin in the middle of the crown. The m3 is about rectangular in shape, but rounded at the back. Although m1 and m2 have two roots, m3 has three.
The Bouldnor Formation is a geological formation in the Hampshire Basin of southern England. It is the youngest formation of the Solent Group and was deposited during the uppermost Eocene and lower Oligocene.
Xiphodon is the type genus of the extinct Palaeogene artiodactyl family Xiphodontidae. It, like other xiphodonts, was endemic to Western Europe and lived from the middle Eocene up to the earliest Oligocene. Fossils from Montmartre in Paris, France that belonged to X. gracilis were first described by the French naturalist Georges Cuvier in 1804. Although he assigned the species to Anoplotherium, he recognized that it differed from A. commune by its dentition and limb bones, later moving it to its own subgenus in 1822. Xiphodon was promoted to genus rank by other naturalists in later decades. It is today defined by the type species X. gracilis and two other species, X. castrensis and X. intermedium.
Plagiolophus is an extinct genus of equoids belonging to the family Palaeotheriidae. It lived in Europe from the middle Oligocene to the early Oligocene. The type species P. minor was initially described by the French naturalist Georges Cuvier in 1804 based on postcranial material including a now-lost skeleton originally from the Paris Basin. It was classified to Palaeotherium the same year but was reclassified to the subgenus Plagiolophus, named by Auguste Pomel in 1847. Plagiolophus was promoted to genus rank by subsequent palaeontologists and today includes as many as seventeen species. As proposed by the French palaeontologist Jean A. Remy in 2004, it is defined by three subgenera: Plagiolophus, Paloplotherium, and Fraasiolophus.
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.
Dichodon is an extinct genus of Palaeogene artiodactyls belonging to the family Xiphodontidae. It was endemic to Western Europe and lived from the middle Eocene up to the earliest Oligocene. The genus was first erected by the British naturalist Richard Owen in 1848 based on dental remains from the fossil beds in Hordle, England. He noticed similar dentitions to contemporary artiodactyls like those of the Anoplotheriidae and Dichobunidae and references the name of the genus Dichobune. Eventually, it was found to be more closely related to Xiphodon and now includes 11 species, although one of them may be synonymous.
Bachitherium is an extinct genus of Paleogene ruminants that lived in Europe from the late Eocene to the late Oligocene. The genus was erected in 1882 by Henri Filhol based on fossil remains found in the Quercy Phosphorites Formation. Bachitherium curtum was defined the type species, and another species called B. insigne; five more species have since been named although one, B. sardus, is currently pending reassessment. The genus name derives from "Bach", the French locality where its first fossils were found, and the Greek θήρ/therium meaning "beast". Bachitherium has historically been assigned to various families within the ruminant infrorder Tragulina, but was reclassified to its own monotypic family Bachitheriidae by Christine Janis in 1987.
Diplobune is an extinct genus of Palaeogene artiodactyls belonging to the family Anoplotheriidae. It was endemic to Europe and lived from the late Eocene to the early Oligocene. The genus was first erected as a subgenus of Dichobune by Ludwig Rütimeyer in 1862 based on his hypothesis of the taxon being a transitional form between "Anoplotherium" secundaria, previously erected by Georges Cuvier in 1822, and Dichobune. He based the genus etymology off of the two-pointed pillarlike shapes of the lower molars, which had since been a diagnosis of it. However, in 1870, Diplobune was elevated to genus rank by Oscar Fraas, who recognized that Diplobune was a distinct genus related to Anoplotherium and not Dichobune. After several revisions of the anoplotheriids, there are currently four known species of which D. minor is the type species.
Ephelcomenus is an extinct genus of Palaeogene artiodactyls endemic to Western Europe. It contains one species E. filholi, which was first described by Richard Lydekker in 1889 but eventually classified to its own genus by the Swiss palaeontologist Johannes Hürzeler in 1938. It has an uncertain stratigraphic range, but some sources suggest that it was present in the Oligocene after the Grande Coupure turnover event of western Europe.
Mixtotherium is an extinct genus of Palaeogene artiodactyls belonging to the monotypic family Mixtotheriidae. Known informally as mixtotheriids or mixtotheres, these artiodactyls were endemic to western Europe and occurred from the middle to late Eocene. The genus and type species were both first established by the French naturalist Henri Filhol in 1880. Several species are well known by good skull fossils, which were informative enough to allow for classifications of the species to their own family. The Mixtotheriidae, first recognized by Helga Sharpe Pearson in 1927, is currently known by 7 valid species, although M. priscum is thought by several authors to be synonymous with M. gresslyi. The affinities of the Mixtotheriidae in relation to other artiodactyl families is uncertain, but it is currently thought to have been related to the Cainotherioidea and Anoplotheriidae.
Haplomeryx is an extinct genus of Palaeogene artiodactyls belonging to the family Xiphodontidae. It was endemic to Western Europe and lived from the middle Eocene up to the earliest Oligocene. Haplomeryx was first established as a genus by the German naturalist Max Schlosser in 1886 based on a molar tooth set from Quercy Phosphorites deposits. Three additional species were erected and classified to the xiphodontid genus while one other species, first recognized in 1822, was tentatively classified to it and remains unresolved in affinity.
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