Furodon
| Furodon | ||||||||||||
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Lower jaw of Furodon (holotype) |
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| Temporal occurrence | ||||||||||||
| Lower to Middle Eocene ( Ypresian to Lutetian ) | ||||||||||||
| 49 to 45 million years | ||||||||||||
| Locations | ||||||||||||
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North Africa (Algeria, Tunisia) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Furodon | ||||||||||||
| Solé , Lhullier , Adaci , Bensalah , Mahboubi & Tabuce , 2014 | ||||||||||||
Furodon is a genus in the order Hyaenodonta , extinct carnivorous mammals that may be close to predators. So far it is known about only a few finds, which are composed of a lower jaw and individual teeth. The remains suggest a small predator . He lived in the transition from the Lower to the Middle Eocene 49 to 45 million years ago in northern Africa . This is the oldest representative of the Teratodontinae to date. The genus was scientifically introduced in 2014. At first she was considered a member of another line of hyaenodonts.
description
Furodon is a small representative of the Hyaenodonta with an estimated body weight of 1.9 kg. So far only the lower jaw and a few individual teeth are known. The horizontal bone body of the lower jaw was relatively low with no major differences between the anterior and posterior sections. The lower edge was slightly convex. The symphysis ended on the third premolar . A mental foramen was formed below the second and below between the third and fourth premolars . The crown process rose almost vertically, the articular process has only partially survived. A deep masseteric fossa was formed on the ascending branch.
The incisors are missing, of the anterior three premolars only the alveoli have survived. The canine was tall and oval in cross-section. There was no diastema between the individual premolars . The last premolar was somewhat elongated in length and highly triangular with a main cusp, the protoconid. This had a slightly asymmetrical shape. Additional humps were rather small. The molars had a typical sectorial shape, the three main cusps comprised the meta-, para- and protoconid. Of these, the protoconide towered the highest, the paraconide was higher than the metaconide. The latter reduced its size from the first to the last molar noticeably. The reduced metaconid differs significantly from Glibzegdouia with its still very large metaconid. The talonid, a deeper part of the chewing surface, was narrow and short, but also had small bumps. In the extent of the talonid, Furodon is more similar to Brychotherium than Glibzegdouia . The last premolar measured 6.3 mm in length. The teeth of the molar row continuously increased in size from front to back, with the first molar slightly shorter than the fourth premolar and the last molar measuring 8.0 mm.
Only a few molars have survived from the upper dentition. The main cusps here consisted of the meta-, para- and protoconus. Typically for the Teratodontinae, the meta- and paraconus were fused together at the base, the tips of the two cusps stood free. In contrast to other members of the subfamily, the Paraconus rose above the Metaconus, but it was less developed overall. Both had a laterally pressed cross-section, which was stronger than Masrasector . The protoconus was well developed. The average length of the first molar was 4.6 mm.
Fossil finds
Furodon has so far only been found in North Africa . The most important finds came to light in Gour Lazib in western Algeria . Gour Lazib, together with Glib Zegdou and Gour Idergane, forms a complex of sites (called “Hammada du Dra”) that extends over 50 km away on the northwestern edge of the Sahara . The first finds here came to the fore in the 1970s, and to date more than 500 fossil remains have been discovered, most of which, however, are in small pieces. The numerous mammal material consists of rodents , primates , bats , snakes and elephants . There are also birds, reptiles, amphibians and fish. Most of the remains come from the Glib-Zegdou Formation . This consists of clay , silt , sand and limestone . According to paleomagnetic studies, it dates back to the transition from the Lower to the Middle Eocene between 49 and 45 million years ago. The Furodon bone material that emerged in the middle section of the Glib-Zegdou Formation includes a lower jaw and individual isolated lower and upper molars. In addition to Furodon , other hyaenodonts have been described, such as Glibzegdouia and Parvavorodon .
Additional finds are documented from Chambi in northeastern Tunisia . There are around half a dozen isolated teeth, including some of the deciduous teeth. Chambi has a comparable age to Gour Lazib, the fossil spectrum is also similar.
Systematics
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Internal systematics of the Teratodontinae according to Solé & Mennecart 2019
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Furodon is a genus from the extinct subfamily of the Teratodontinae within the also extinct order of the Hyaenodonta . Originally, the Hyaenodonta formed part of the Creodonta , some of which are sometimes misleadingly referred to as "primal predators". The Creodonta were seen as the sister group of today's carnivores within the parent group of the Ferae . However, the Creodonta turned out to be a non-self-contained group in the following years , they were therefore split into the Hyaenodonta and the Oxyaenodonta . For both groups, one against predators further rearward shifted in the dentition is refractive shear characteristic in the Hyaenodonten this was frequently out of the second upper jaw and the third molars. The hyaenodonts first appeared in the Middle Paleocene around 60 million years ago, they disappeared again in the Middle Miocene around 9 to 10 million years ago. The Teratodontinae are to be understood within the Hyaenodonta as the sister group of the Hyainailouridae family . Both together form the superordinate group of the Hyainailouroidea . The structure of the maxillary molars is characteristic of the Teratodontinae. In these, the para and metaconus merge at the base, the latter usually towering over the former. In contrast to this, in the Hyainailouridae the Para- and Metaconus are united to the Amphiconus, in addition the Paraconus is higher than the Metaconus. In terms of the height of the two cusps, the Teratodontinae agree with the Hyaenodontidae , but in these the Para- and Metaconus are also fused to form an Amphiconus. Furodon is considered to be very basal within the Teratodontinae and, according to some phylogenetic studies, is compared to all other representatives of the subfamily as a sister taxon. According to other phylogenetic analyzes, the genus forms a common clade as a basal teratodontine with the relatives around Metasinopa .
The genus Furodon was first scientifically described in 2014 by Floréal Solé and research colleagues . The basis was the found material from Gour Lazib in Algeria with the left lower jaw branch as a holotype (specimen number HGL 50bis-56). The generic name is made up of the Latin word for for "thief" and the Greek word ὀδούς ( odū́s ) for "tooth". The only known species so far is Furodon crocheti . This was named after Jean-Yves Crochet , who had scientifically worked on numerous mammals of the Paleogene , including some hyaenodonts. In the first description, Solé's team identified Furodon as an ancient representative of the Hyainailourinae, which was justified, among other things, with the reduction in size of the talonid and the size reduction of the metaconid on the lower molars. Later phylogenetic investigations could only partially confirm this position, as they ascribed the genus a mediator role between the Hyainailourinae and the Teratodontinae. Other, far more extensive analyzes, however, see furodon as a basal member of the Teratodontinae. This classification results from the less simplified Talonid with individual marginal humps and the small but clearly developed Metaconid, which is mostly completely reduced in the Hyainailourines. As a result, the Furodon dentition does not appear as clearly hypercarnivorous as it is the case with the Hyainailourinen and, in addition to a cutting function, also has a piercing and breaking function. Furodon is the oldest known representative of the Teratodontinae.
literature
- Floréal Solé, Julie Lhuillier, Mohammed Adaci, Mustapha Bensalah, M'hammed Mahboubi and Rodolphe Tabuce: The hyaenodontidans from the Gour Lazib area (? Early Eocene, Algeria): implications concerning the systematics and the origin of the Hyainailourinae and Teratodontinae. Journal of Vertebrate Paleontology 12 (3), 2014, pp. 303-322
Individual evidence
- ↑ a b c d e Floréal Solé, Julie Lhuillier, Mohammed Adaci, Mustapha Bensalah, M'hammed Mahboubi and Rodolphe Tabuce: The hyaenodontidans from the Gour Lazib area (? Early Eocene, Algeria): implications concerning the systematics and the origin of the Hyainailourinae and Teratodontinae. Journal of Vertebrate Paleontology 12 (3), 2014, pp. 303-322
- ↑ Matthew R. Borths and Erik R. Seiffert: craniodental and humeral morphology of a new species of Masrasector (Teratodontinae, Hyaenodonta, Placentalia) from the late Eocene of Egypt and locomotor diversity in hyaenodonts. PLoS ONE 12 (4), 2017, p. E0173527, doi: 10.1371 / journal.pone.0173527
- ^ J. Sudre: Nouveaux mammifères éocènes du Sahara occidental. Palaeovertebrata 9, 1979, pp. 83-115
- ↑ Mohammed Adaci, Rodolphe Tabuce, Fateh Mebrouk, Mustapha Bensalah, Pierre-Henri Fabre, Lionel Hautier, Jean-Jacques Jaeger, Vincent Lazzari, M'hammed Mahboubic, Laurent Marivaux, Olga Otero, Stéphane Peigné and Haiyan Tong: Nouveaux sites à vertébrés paleogènes dans la region des Gour Lazib (Sahara north-occidental, Algérie). Comptes Rendus Palevol 6, 2007, pp. 535-544
- ↑ Pauline Coster, Mouloud Benammia, Mohammed Adaci, Rodolphe Tabuce, Laurent, Marivaux, Mohammed Mahboubi, Mustapha Bensalah, Salamet Mahboubi, Abdou Mahboubi, Cheikh Maameri and Jean-Jacques Jaeger: Magnetic polarity stratigraphy and age of the Early-middle continental Eocene deposits of el Kohol and Gour Lazib (Algeria). Geological Society of America Bulletin 124, 2012, pp. 1590-1606
- ↑ Mohammed Adaci, Mustapha Bensalah, Rodolphe Tabuce, Fateh Mebrouk, Laurent Marivaux, Olga Otero, Djamila Zaoui, Madani Benyoucef and Mahammed Mahboubi: L'Éocène continental du complexe de Gour Lazib (Sahara North-Occidental, Algérie). Mémoire du Service Géologique de l'Algérie 19, 2016, pp. 63–89
- ↑ Floréal Solé, El Mabrouk Essid, Wissem Marzougui, Rim Temani, Hayet Khayati Ammar, Mhammed Mahboubi, Laurent Marivaux, Monique Vianey-Liaud and Rodolphe Tabuce: New fossils of Hyaenodonta (Mammalia) from the Eocene localities of Chambi (Tunisia) and Biri el Ater (Algeria), and the evolution of the earliest African hyaenodonts. Palaeontologia Electronica 19 (3), 2016, p. 41A ( [1] )
- ↑ a b Floréal Solé and Bastien Mennecart: A large hyaenodont from the Lutetian of Switzerland expands the body mass range of the European mammalian predators during the Eocene. Acta Palaeontologica Polonica 64, 2019, doi: 10.4202 / app.00581.2018
- ↑ Kenneth D. Rose: The beginning of the age of mammals. Johns Hopkins University Press, Baltimore, 2006, pp. 1–431 (pp. 122–126)
- ↑ Michael Morlo, Gregg Gunnell, and P. David Polly: What, if not nothing, is a creodont? Phylogeny and classification of Hyaenodontida and other former creodonts. Journal of Vertebrate Paleontology 29 (3 suppl), 2009, p. 152A
- ↑ Floréal Solé: New proviverrine genus from the Early Eocene of Europe and the first phylogeny of Late Paleocene-Middle Eocene hyaenodontidans (Mammalia). Journal of Systematic Paleontology 11, 2013, pp. 375-398
- ↑ Floréal Solé, Eli Amson, Matthew Borths, Dominique Vidalenc, Michael Morlo and Katharina Bastl: A New Large Hyainailourine from the Bartonian of Europe and Its Bearings on the Evolution and Ecology of Massive Hyaenodonts (Mammalia). PLoS ONE 10 (9), 2015, p. E0135698, doi: 10.1371 / journal.pone.0135698
- ↑ a b Matthew R. Borths, Patricia A. Holroyd and Erik R. Seiffert: Hyainailourine and teratodontine cranial material from the late Eocene of Egypt and the application of parsimony and Bayesian methods to the phylogeny and biogeography of Hyaenodonta (Placentalia, Mammalia). PeerJ 4, 2016, p. E2639, doi: 10.7717 / peerj.2639
- ↑ Matthew R. Borths and Nancy J. Stevens: The first hyaenodont from the late Oligocene Nsungwe Formation of Tanzania: Paleoecological insights into the Paleogene-Neogene carnivore transition. PLoS ONE 12 (10), 2017, p. E0185301, doi: 10.1371 / journal.pone.0185301
- ↑ Rajendra S. Rana, Kishor Kumar, Shawn P. Zack, Floreal Solé, Kenneth D. Rose, Pieter Missiaen, Lachham Singh, Ashok Sahni and Thierry Smith: Craniodental and Postcranial Morphology of Indohyaenodon raoi from the Early Eocene of India, and Its Implications for Ecology, Phylogeny, and Biogeography of Hyaenodontid Mammals. Journal of Vertebrate Paleontology 35 (5), 2015, p. E965308, doi: 10.1080 / 02724634.2015.965308
