Homogalax

Homogalax
Temporal range: Early Eocene
H. tapirinus, Wyoming. At the AMNH.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Perissodactyla
Family: Isectolophidae
Genus: Homogalax
Hay, 1899
Species
  • H. protapirinus

Homogalax (from the Greek "ὁμογάλαξ") is an extinct genus of tapir-like odd-toed ungulate. It was described on the basis of several fossil finds from the northwest of the United States, whereby the majority of the remains come from the state of Wyoming. The finds date to the Lower Eocene between 56 and 48 million years ago. In general, Homogalax was very small, only reaching the weight of today's peccaries, with a maximum of 15 kg. Phylogenetic analysis suggests the genus to be a basal member of the clade that includes today's rhinoceros and tapirs (collectively called Ceratomorpha). In contrast to these, Homogalax was adapted to fast locomotion.[1]

Taxonomy

Homogalax is a genus from the order Perissodactyla. It is a basal representative, usually placed in the potentially paraphyletic family Isectolophidae.[2] If the paraphyletic position is correct, Homogalax nests as more derived than most other isectolophids, with only Cardiolophus and Orientolophus, and a clade including Karagalax and Gandheralophus, being closer to the Ceratomorpha.

Below is a phylogenetic tree based on Bai et al (2020), with particular focus on the Isectolophidae (recovered as paraphyletic).[2]

Today, one species of the genus Homogalax is recognized: H. protapirinus (Wortman, 1896).[3] Other species such as H. tapirinus and H. primaevus have been described in the past, but are considered to be synonyms of H. protapirinus. Species in Asia were also named, such as H. namadicus and H. wutuensis,[4] but these are now to be regarded as representatives of basal chalicotheres such as Protomoropus.[5] Another species, H. reliquius, was later identified as a specimen of Isectolophus.[6]

Description

E is lower dentition of H. protapirinus

Homogalax was a small representative of the basal odd-toed ungulates. In general, it resembled other, basal forms of the order Perissodactyla, such as Hyracotherium or Sifrhippus, some of which were well-studied members of the early equids, what shows the very basal position within the odd ungulate. A body weight of 9.5 to 15.1 kg can be assumed on the basis of various skeletal elements.[7] Homogalax is known from numerous fossil finds, which however only partially contain complete material. Underneath is a heavily weathered skull, which, however, shows few skeletal features. This is around 15 cm long and relatively flat, and overall it was similar to that of Hyracotherium . The short premaxilla, which rose steeply and came into contact with the nasal bone, was typical, which is not the case with today's Ceratomorpha (tapirids and rhinocerotids). The ascending central jawbone formed the back of the interior of the nose, which is also unknown in today's odd-toed ungulates. As a result, the nasal bone had only a short extension to the front and only slightly exceeded the canine. The occiput had a distinctly short shape, while the zygomatic arch hardly protruded outwards, instead running parallel to the skull.[3] [1]

The dentition includes the complete set of the early placental mammals. The incisors were chisel-shaped and small, but varied in size. In general, the third (outermost) incisor became the largest. The canine usually had a long and pointed shape and was somewhat pressed on the side. A short, less than 1 cm long diastema occurred to the rear dentition only rarely; others could be observed between the last incisor and the canine as well as between the first two premolars. The premolars themselves were completely unmolarized, meaning they did not resemble the molars, and only had a raised enamel cusp on the chewing surface. The molars were characterized by low (brachyodont) tooth crowns and two tapir-like transverse tooth enamel ridges (bilophodont), which could also be inclined in the lower jaw. The length of the teeth increased towards the back. The first premolar was around 0.6 cm long, the last molar up to 1.7 cm long.[8][9]

A complete skeleton is not available, but skulls and some postcrania have been preserved. Of particular note among the latter are the long bones. The humerus was built long and narrow and measured about 13 cm. The thigh bone on the other hand reached a length of 15 cm and typically had a third trochanter, which is typical for odd-toed ungulates, but was not yet so prominent in "Homogalax". The shin became as long as the thigh bone. The forefoot consisted of four digits with a very pronounced central toe (metacarpus III). The laterally attached digits (metacarpus II and IV), however, were somewhat reduced in length, the outermost digit (metacarpus V) was greatly reduced. The hind foot, on the other hand, had only three digits, but also had a strong central ray (metatarsus III). Compared to the anterior feet, the posterior ones were around 30% longer (metacarpus III length is 5.1 cm to metatarsus III's 6.7 cm). The individual phalanges of the toes are extremely long. Four-toed front and three-toed hind feet are typical of primitive odd-toed ungulates and are now only found in the tapirs.[7][3]

Distribution

Finds of Homogalax are largely only known from North America and come from the Lower Eocene 56 to 48 million years ago (locally stratigraphically called Lower Wastachian). They show that Homogalax was a regular but not frequent element of the fauna at that time. In the state of Wyoming in particular, numerous fossils have been recovered. The remains from the Willwood Formation of the Bighorn Basin are of great importance, including more than 100 fragments from several individuals, including a complete skull, which is one of the few well-preserved Homogalax fossils. This also includes the majority of known postcranial skeletal finds, such as individual long bones, a complete foot and hand skeleton and parts of the pelvis and shoulder blades. Other remains are from the Washakie Basin, as well as from the Powder River Basin; both sites, however, contained mostly only isolated teeth. Remnants of the Golden Valley Formation in North Dakota have been reported outside Wyoming.[8][1][7] Far away from these sites, the northernmost finds of Homogalax come from the Margaret Formation on the Ellesmere Island in the far north of Canada. They include, among other things, individual teeth.[10]

Paleobiology

Based on the teeth, only a few differences in size and shape can be discerned in specimens of Homogalax. However, the canine varies in size, which can be interpreted as sexual dimorphism. This is unconfirmed, though, as there are also intermediate-length canines.[8] The lower legs, especially on the hindlimbs, show adaptations to a cursorial lifestyle. Among other things, especially pronounced joint surfaces on the ankle bone ensured that the foot remained stable in the longitudinal direction and did not twist sideways at high walking speed. A permanent running gait within the odd-toed ungulates is generally believed to be an ancient characteristic and is only practised today by the highly specialized horses.[7]

References

  1. ^ a b c Holbrook, LT; Lucas, SG; and Emry, RJ; "Skulls of the Eocene Perissodactyls (Mammalia) Homogalax and Isectolophus." Journal of Vertebrate Paleontology 24. (4) 951-956.
  2. ^ a b Bai, Bin; Meng, Jin; Zhang, Chi; Gong, Yan-Xin; Wang, Yuan-Qing (2020). "The origin of Rhinocerotoidea and phylogeny of Ceratomorpha (Mammalia, Perissodactyla)". Communications Biology. 3 (1): 509. doi:10.1038/s42003-020-01205-8. ISSN 2399-3642. PMC 7490376. PMID 32929169.
  3. ^ a b c Holbrook, Lt; 2001 "Comparative osteology of early Tertiary tapiromorphs (Mammalia, Perissodactyla)." Zoological Journal of the Linnean Society 132. 1-54.
  4. ^ Minchen, C; Chuan-kuei, L; 1965 "Homogalax and Heptodon of Shantung." Vertebrata Palasiatica. 9 (1), 15-22.
  5. ^ Hooker, JJ; Dashzeveg, D; 2004 "The origin of chalicotheres (Perissodactyla, Mammalia)." Palaeontology. 47 (6): 1363-1386.
  6. ^ Lucas, SG; Holbrook, T; Emry, RJ; 2003 "Isectolophus (Mammalia, Perissodactyla) from the Eocene of the Zaysan Basin, Kazakhstan and its biochronological significance. Journal of Vertebrate Paleontology. 23 (1): 238-243.
  7. ^ a b c d Rose, KD; 1996 "Skeleton of early Eocene Homogalax and the origin of Perissodactyla. Palaeovertebrata 25 (2-4).243-260.
  8. ^ a b c Radinsky, LB; 1963 "Origin and Early Evolution of the North American Tapiroidea." Peabody Museum of Natural History Yale University Bulletin 17. 1-106.
  9. ^ Schoch, RM; 1989 "A review of the Tapiroids." In: Prothero, DR; Schoch, RM; "The evolution of Perissodactyls". New York and Oxford." 298-320.
  10. ^ Eberle, JJ; Eberth, DA; 2015 "Additions to the Eocene Perissodactyla of the Margaret Formation, Eureka Sound GRroup, Ellesmere Island, Arctic Canada." Canadian Journal of Earth Sciences 52. 123-133.

Read other articles:

Добропільська міська громадаОсновні даніКраїна  УкраїнаОбласть Донецька областьРайон Покровський районКод КАТОТТГ UA14160070000097326Утворена 12 червня 2020 рокуАдмін. центр ДобропілляТериторія та населенняПлоща 265,5 км²Населення 43 827 осібНаселені пунктиМіста 2Смт 2Се...

 

German noble family You can help expand this article with text translated from the corresponding article in German. (January 2020) Click [show] for important translation instructions. View a machine-translated version of the German article. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text int...

 

Shamsuddin Muhammad Atgah Khan (meninggal 16 Mei 1562), juga dikenal sebagai Khan-e-Kalan Shamsu'd-Din Muhammad Khan Atgah Khan, adalah tokoh terkemuka di istana kaisar Mughal, Akbar. Khan-e-KalanShamsuddin Muhammad KhanAtaga KhanMeninggal16 Mei 1562MakamKompleks Nizamuddin Dargah, DelhiPekerjaanWakil Kekaisaran MughalGelarKhan-e-KalanSuami/istriJiji AngaAnakMirza Aziz KokaOrang tuaMir Yar Muhammad Dia memegang posisi penting di istana Akbar, termasuk sebagai wakil (penasihat atau menteri), y...

Chronologie de la France ◄◄ 1714 1715 1716 1717 1718 1719 1720 1721 1722 ►► Chronologies Portrait de Louis XV, Jean Ranc, 1718.Données clés 1715 1716 1717  1718  1719 1720 1721Décennies :1680 1690 1700  1710  1720 1730 1740Siècles :XVIe XVIIe  XVIIIe  XIXe XXeMillénaires :-Ier Ier  IIe  IIIe Chronologies thématiques Art Architecture, Arts plastiques (Dessin, Gravure, Peinture et Sculpture), Littérature, Musique classique e...

 

العلاقات الباكستانية الكورية الشمالية باكستان كوريا الشمالية   باكستان   كوريا الشمالية تعديل مصدري - تعديل   العلاقات الباكستانية الكورية الشمالية هي العلاقات الثنائية التي تجمع بين باكستان وكوريا الشمالية.[1][2][3][4][5] مقارنة بين البلدين ...

 

Georgian politician and publicist Akaki Chkhenkeliაკაკი ჩხენკელი (Georgian)Autochrome portrait by Auguste Léon, 1921Prime Minister of the Transcaucasian Democratic Federative RepublicIn office26 April 1918 – 26 May 1918Preceded byOffice establishedSucceeded byOffice abolishedMinister of Foreign Affairs of the Transcaucasian Democratic Federative RepublicIn office26 April 1918 – 26 May 1918Preceded byOffice establishedSucceeded byOffice abo...

Flag of the Opole Voivodeship, Poland Opole VoivodeshipUsecivil flagProportion5:8Adopted21 December 2004Designtwo horizontal stripes, with yellow on the top, and blue at the bottom, of which, the top stripe is twice the size of the bottom oneDesigned byMichał Marciniak-Kożuchowski Usestate flagProportion5:8Adopted21 December 2004Designtwo horizontal stripes, with yellow on the top, and blue at the bottom, of which, the top stripe is twice the size of the bottom one, with a coat of arms...

 

Sutjipto Menteri PertanianMasa jabatan28 Juli 1966 – 10 Juni 1968PresidenSoehartoPendahuluFrans SedaPenggantiThoyib Hadiwidjaja Informasi pribadiLahir4 Desember 1926 (umur 97)Boyolali, Jawa TengahKarier militerPihak IndonesiaDinas/cabang TNI Angkatan DaratMasa dinas1957 – 1976Pangkat Mayor Jenderal TNISatuanKorps Kehakiman (CKH)Sunting kotak info • L • B Mayor Jenderal TNI (Purn.) Sutjipto merupakan seorang perwira tinggi, politikus, dan ...

 

artikel ini perlu dirapikan agar memenuhi standar Wikipedia. Tidak ada alasan yang diberikan. Silakan kembangkan artikel ini semampu Anda. Merapikan artikel dapat dilakukan dengan wikifikasi atau membagi artikel ke paragraf-paragraf. Jika sudah dirapikan, silakan hapus templat ini. (Pelajari cara dan kapan saatnya untuk menghapus pesan templat ini) Bagian dari serial Agama Buddha Mahāyāna Negara India • Tiongkok • JepangKorea • VietnamRepublik Tiongkok...

كالوست كولبنكيان كالوست سركيس كولبنكيان معلومات شخصية اسم الولادة (بhyw: Գալուստ Սարգիս Կիւլպէնկեան)‏  الميلاد 23 مارس 1869(1869-03-23)الآستانة،  الدولة العثمانية الوفاة 22 يونيو 1955 (86 سنة)لشبونة،  البرتغال الإقامة مهندس بترول مواطنة الدولة العثمانية المملكة المتحدة لبريط...

 

Venus figurines of ZarayskVenus figurine No. 1 from ZarayskMaterialMammoth ivoryCreated22,000 to 16,000 yearsDiscovered2005Zaraysk, Moscow Oblast, RussiaDiscovered byHizri Amirkhanov and Sergey Lev The Venus figurines from Zaraysk are two paleolithic sculptures of the female body.[1] Both are made of mammoth ivory. The age of these Venus figurines is about 20,000 to 14,000 years BC; they stem from the Gravettian. Zaraysk is a Russian town located between Moscow and Ryazan. The statuet...

 

この項目には、一部のコンピュータや閲覧ソフトで表示できない文字が含まれています(詳細)。 数字の大字(だいじ)は、漢数字の一種。通常用いる単純な字形の漢数字(小字)の代わりに同じ音の別の漢字を用いるものである。 概要 壱万円日本銀行券(「壱」が大字) 弐千円日本銀行券(「弐」が大字) 漢数字には「一」「二」「三」と続く小字と、「壱」「...

Coppa del Mondo per club FIFA 20072007FIFAクラブワールドカップ2007 FIFA kurabuwārudokappu Competizione Coppa del mondo per club FIFA Sport Calcio Edizione 4ª Organizzatore FIFA Date 7 - 16 dicembre 2007 Luogo  Giappone Partecipanti 7 Sito web Sito ufficiale Risultati Vincitore Milan(1º titolo) Finalista Boca Juniors Terzo Urawa Reds Quarto Étoile du Sahel Statistiche Miglior giocatore Kaká Miglior marcatore Washington (3) Incontri disputati 7 Gol segnati 21...

 

Lockheed X-17 adalah roket penelitian tiga tahap berbahan bakar padat untuk menguji efek dari mach atmosfer masuk kembali. Tahap pertama dari X-17 membawa roket ke ketinggian 17 mil (27 km) sebelum terbakar habis. Roket kemudian akan Coast pada momentum untuk sekitar 100 mil (160 km) sebelum mengorek bawah untuk masuk kembali. Mesin tahap kedua kemudian akan dinyalakan sebelum jettisoning dan memicu tahap ketiga dan terakhir. Pada tanggal 24 April 1957, X-17 mencapai kecepatan 9.00...

 

This article is about the media player software. For the music and video streaming service, see Apple Music. For the discontinued portable media player line, see iPod. For the concept, see Media player software. For other uses, see Music (disambiguation). Media player developed by Apple MusicLibrary tab in the Music app for iOS 16Developer(s)Apple Inc.Initial releaseiOS: June 29, 2007; 16 years ago (2007-06-29) (iPod) October 12, 2011; 12 years ago (2011-10...

The Battle of Copenhagen. Painting by Carl Neumann The Hope (Danish: Håbet) is a work for brass band, percussion, choir, and organ written in 2001 by Frederik Magle, depicting the Battle of Copenhagen in 1801. It consists of two movements with the first being purely instrumental. The choir enters in the second movement using text from Psalm 27. The music was commissioned by the Admiral Danish Fleet (Royal Danish Navy Operational Command) for the 200th anniversary of the battle in 2001. The H...

 

Artikel ini perlu diwikifikasi agar memenuhi standar kualitas Wikipedia. Anda dapat memberikan bantuan berupa penambahan pranala dalam, atau dengan merapikan tata letak dari artikel ini. Untuk keterangan lebih lanjut, klik [tampil] di bagian kanan. Mengganti markah HTML dengan markah wiki bila dimungkinkan. Tambahkan pranala wiki. Bila dirasa perlu, buatlah pautan ke artikel wiki lainnya dengan cara menambahkan [[ dan ]] pada kata yang bersangkutan (lihat WP:LINK untuk keterangan lebih lanjut...

 

Japanese breakfast dish of rice and egg Tamago kake gohan (left), along with tsukemono and miso soup Tamago kake gohan (卵かけご飯, egg on rice) is a popular Japanese breakfast food consisting of cooked Japanese rice topped or mixed with raw egg and soy sauce. Background Tamago kake gohan is a dish in which a raw egg is put on top of or mixed with rice, or a recipe for such a dish.[1] Beaten eggs are sometimes used, as are non-beaten. Sometimes only the yolk of the egg is used. T...

فريق برتلينج النفاث   الموقع الرسمي الموقع الرسمي  تعديل مصدري - تعديل   يعد فريق برتلينج النفاث، (بالإنجليزية: Breitling Jet Team)‏.[1] أكبر فريق عرض للألعاب الجوية في أوروبا. مقرها في ديجون ، فرنسا ، وهي تطير سبع طائرات آيرو إل-39 ألباتروس التشيكية. الفريق يحلق الفريق في ع...

 

Annual reception held at the White House White House, South Facade HanukkahA Hanukkah menorah (9-branch candelabra)Official nameHebrew: חֲנֻכָּה or חנוכה English translation: Establishing or Dedication (of the Temple in Jerusalem)Also calledFestival of Lights, Festival of DedicationObserved byJewsCelebrationsLighting the lights on the branches of the Hanukkah menorah (Hanukkiyah). Special foods, prayers, and songs.Begins25 Kislev on the Jewish calendarEnds8 days later: 2 Tev...