Acheloma

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Acheloma
Temporal range: Early Permian, 279.5–272.5  Ma
Acheloma-Field Museum.jpg
Skeletal mount of A. cumminsi, Field Museum of Natural History
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Temnospondyli
Family: Trematopidae
Genus: Acheloma
Cope, 1882
Species
  • A. cumminsi Cope, 1882
  • A. dunniPolley & Reisz, 2011
Synonyms

Trematops milleriWilliston, 1909Trematops thomasiMehl, 1926Trematops willistoniOlson, 1941Trematops stoneiWilliston, 1970

Contents

Restoration of A. cumminsi Acheloma 12DB.jpg
Restoration of A. cumminsi

Acheloma (also known as Trematops milleri) is an extinct genus of temnospondyl that lived during the Early Permian. [1] The type species is A. cumminsi.

History of study

Acheloma was named by Edward Drinker Cope in 1882 based on a partial skull with associated postcranial elements from the Arroyo Formation of Texas; [2] the specimen is currently reposited at the American Museum of Natural History in New York. Subsequent discoveries of large trematopids from the Arroyo Formation were named as different species of Trematops (T. milleri, T. willistoni), but these have since been synonymized with Acheloma cumminsi. Trematops stonei from the Washington Formation of Ohio and Trematops thomasi from Oklahoma have also been synonymized with A. cumminsi. A second species of Acheloma was described by Polley & Reisz (2011) from the Richards Spur locality in Oklahoma. [3]

Anatomy

Schoch & Milner (2014) provide nine characters in their diagnosis of Acheloma: (1) toothed crest on the vomer extending medial to the internal naris; (2) constricted otic notch with nearly horizontal ventral margin; (3) preorbital region twice as long as the skull table; (4) naris twice as long as the orbit; (5) posterior skull table wide and posterolaterally expanded; (6) skull margin widens at level of and posterior to orbit; (7) palatine and ectopterygoid with tall fangs; (8) large intervomerine fenestra; and (9) choana elongate and curved with a Y-shaped contour. [4] Acheloma cumminsi and A. dunni are distinguished by the purported absence of lateral exposures of the palatine (LEP) and the ectopterygoid (LEE) in A. cumminsi, [3] but these exposures were subsequently identified following re-examination of the holotype of this taxon. [5]

Ecology

Various analyses have confirmed hypotheses that Acheloma was a terrestrial temnospondyl. [6] [7]

Phylogeny

The following cladogram shows the phylogenetic position of Acheloma, from Polley & Reisz, 2011. [3]

Dissorophoidea  

Sclerocephalus haeuseri

Micromelerpeton credneri

Micropholis stowi

Eoscopus lockardi

  Olsoniformes  

Cacops morrisi

  Trematopidae  

Phonerpeton pricei

 Acheloma 

Acheloma cumminsi

Acheloma dunni

Actiobates peabodyi

Ecolsonia cutlerensis

Anconastes vesperus

Tambachia trogallas


Related Research Articles

<i>Cacops</i> Extinct genus of amphibians

Cacops, is a genus of dissorophid temnospondyls from the Kungurian stage of the early Permian of the United States. Cacops is one of the few olsoniforms whose ontogeny is known. Cacops fossils were almost exclusively known from the Cacops Bone Bed of the Lower Permian Arroyo Formation of Texas for much of the 20th century. New material collected from the Dolese Brothers Quarry, near Richards Spur, Oklahoma in the past few decades has been recovered, painting a clearer picture of what the animal looked and acted like.

<span class="mw-page-title-main">Dissorophidae</span> Extinct family of amphibians

Dissorophidae is an extinct family of medium-sized, temnospondyl amphibians that flourished during the late Carboniferous and early Permian periods. The clade is known almost exclusively from North America.

<span class="mw-page-title-main">Temnospondyli</span> Ancestors of modern amphibians adapted to life on land

Temnospondyli or temnospondyls is a diverse ancient order of small to giant tetrapods — often considered primitive amphibians — that flourished worldwide during the Carboniferous, Permian and Triassic periods, with fossils being found on every continent. A few species continued into the Jurassic and Early Cretaceous periods, but all had gone extinct by the Late Cretaceous. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are amphibians, many had characteristics such as scales and armour-like bony plates that distinguish them from the modern soft-bodied lissamphibians.

<i>Actinodon</i> Extinct genus of amphibians

Actinodon is an extinct genus of eryopoidean temnospondyl within the family Eryopidae.

<i>Chenoprosopus</i> Genus of amphibians

Chenoprosopus is a genus of extinct cochleosauridae that lived during late Carboniferous and early Permian periods. Two known species of Chenoprosopus are C. milleri and C. lewisi. Chenoprosopus lewisi was described in the basis of a virtually complete skull with maximum skull length of 95 mm. It is significantly smaller than Chenoprosopus milleri and was differentiated from that taxon by Hook (1993) based on sutural patterns of the skull roof. Hook also mentioned the reduced size of the vomerine tusks differentiated C. lewisi from C. milleri, but the different size of these tusks may be different ontogenetic stages of growth. Many of other cochleosaurids from the same time period have an elongated vomer and wide and elongate choana. However, Chenoprosopus is distinguished by its more narrowly pointed snout and separation between the nasal from the maxilla by the broad lacrimal-septomaxilla contact.

<span class="mw-page-title-main">Trematopidae</span> Extinct family of amphibians

Trematopidae is a family of dissorophoid temnospondyl spanning the late Carboniferous to the early Permian. Together with Dissorophidae, the family forms Olsoniformes, a clade comprising the medium-large terrestrial dissorophoids. Trematopids are known from numerous localities in North America, primarily in New Mexico, Oklahoma, and Texas, and from the Bromacker quarry in Germany.

<i>Anconastes</i> Extinct genus of amphibians

Anconastes is an extinct genus of dissorophoid temnospondyl within the family Trematopidae. It is known from two specimens from the Late Carboniferous Cutler Formation of north-central New Mexico in the southwestern United States. The genus name derives from two Greek roots, ankos and nastes ("inhabitant"), which refers to the type locality of El Cobre Canyon where the specimens were found. The specific name is derived from the Latin word vesperus ("western"). The more complete specimen, the holotype, is a partial skull with articulated mandibles and a substantial amount of the postcranial skeleton. The less complete specimen, the paratype, consists only of the right margin of the skull with an articulated mandible.

Actiobates is an extinct genus of trematopid temnospondyl that lived during the Late Carboniferous. It is known from the Garnett Quarry in Kansas.

<i>Ecolsonia</i> Extinct genus of amphibians

Ecolsonia is an extinct genus of trematopid temnospondyl. Its phylogenetic position within Olsoniformes has been historically debated, but it is presently considered to be a trematopid.

<i>Phonerpeton</i> Extinct genus of amphibians

Phonerpeton is an extinct genus of dissorophoid temnospondyl within the family Trematopidae that is known from the early Permian of Texas.

Tersomius is an extinct genus of dissorophoid temnospondyl within the family Micropholidae. It is known from the early Permian of North America.

Pasawioops is an extinct genus of early Permian dissorophoid temnospondyl within the clade Amphibamiformes.

<i>Rubeostratilia</i> Extinct genus of amphibians

Rubeostratilia is an extinct genus of amphibamiform temnospondyl from the early Permian of Texas. It is known from a single skull. This genus was named by Hélène Bourget and Jason S. Anderson in 2011, and the type species is Rubeostratilia texensis. The genus name comes from the Latin translation of 'redbeds' in reference to the Texas redbeds that produced both the holotype and many other early Permian fossils. The specific name is for the state of Texas. The holotype and only known specimen was collected in 1941 from the Nocona Formation exposures in Clay County by a Works Projects Administration project that was transferred to the Field Museum of Natural History through an interinstitutional exchange with the Texas Memorial Museum.

<span class="mw-page-title-main">Olsoniformes</span> Taxon of temnospondyl amphibians (fossil)

Olsoniformes is a clade of dissorophoid temnospondyls, including the families Dissorophidae and Trematopidae. Most members of the clade were highly adapted to a terrestrial lifestyle. The clade was named in 2008 and is defined as the least inclusive clade containing Dissorophus multicinctus and Acheloma cumminsi but not Amphibamus grandiceps, Micromelerpeton credneri, or Apateon pedestris. Olsoniforms share various features such as a stout and low ilium and a thin cultriform process. The earliest-branching olsoniform is Palodromeus bairdi, from the Late Carboniferous of Ohio.

Parioxys is an extinct genus of temnospondyl amphibian from the Early Permian of Texas.

Nanobamus is an extinct genus of amphibamiform temnospondyl amphibian. The type species is Nanobamus macrorhinus. The type specimen is UCLAVP 3686, a skull recovered from the Lower Permian Arroyo Formation.

<span class="mw-page-title-main">Amphibamiformes</span> Extinct clade of amphibians

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<span class="mw-page-title-main">Richards Spur</span>

Richards Spur is a Permian fossil locality located at the Dolese Brothers Limestone Quarry north of Lawton, Oklahoma. The locality preserves clay and mudstone fissure fills of a karst system eroded out of Ordovician limestone and dolomite, with the infilling dating to the Artinskian stage of the early Permian (Cisuralian), around 289 to 286 million years ago. Fossils of terrestrial animals are abundant and well-preserved, representing one of the most diverse Paleozoic tetrapod communities known. A common historical name for the site is Fort Sill, in reference to the nearby military base. Fossils were first reported at the quarry by workers in 1932, spurring a wave of collecting by local and international geologists. Early taxa of interest included the abundant reptile Captorhinus and microsaurs such as Cardiocephalus and Euryodus. Later notable discoveries include Doleserpeton, the most diverse assortment of parareptiles in the Early Permian, and the rare early diapsid Orovenator.

This list of fossil amphibians described in 2020 is a list of new taxa of fossil amphibians that were described during the year 2020, as well as other significant discoveries and events related to amphibian paleontology that occurred in 2020.

References

  1. Reisz, Robert; Dilkes, David William (1987). "Trematops milleri Williston, 1909, identified as a junior synonym of Acheloma cumminsi Cope, 1882 : with a revision of the genus". American Museum Novitates (2902): 1–12. hdl:2246/5185.
  2. Cope, E. D. (1882). "Third Contribution to the History of the Vertebrata of the Permian Formation of Texas". Proceedings of the American Philosophical Society. 20 (112): 447–461. ISSN   0003-049X. JSTOR   982692.
  3. 1 2 3 Polley, B.P.; and Reisz, R.R. (2011). "A new Lower Permian trematopid (Temnospondyli: Dissorophoidea) from Richards Spur, Oklahoma". Zoological Journal of the Linnean Society. 161 (4): 789–815. doi: 10.1111/j.1096-3642.2010.00668.x . hdl: 1807/18982 .
  4. Schoch, Rainer R.; Milner, Andrew R. (2014). Sues, Hans-Dieter (ed.). Handbuch der Paläoherpetologie Part 3A2. Temnospondyli I. Stuttgart: Verlag Dr. Friedrich Pfeil. ISBN   9783931516260. OCLC   580976.
  5. Gee, Bryan M.; Bevitt, Joseph J.; Reisz, Robert R. (2019-03-12). "A Juvenile Specimen of the Trematopid Acheloma From Richards Spur, Oklahoma and Challenges of Trematopid Ontogeny". Frontiers in Earth Science. 7: 38. Bibcode:2019FrEaS...7...38G. doi: 10.3389/feart.2019.00038 . ISSN   2296-6463.
  6. Sanchez, S.; Germain, D.; De Ricqlès, A.; Abourachid, A.; Goussard, F.; Tafforeau, P. (2010). "Limb-bone histology of temnospondyls: implications for understanding the diversification of palaeoecologies and patterns of locomotion of Permo-Triassic tetrapods: Diversification of early tetrapod locomotion". Journal of Evolutionary Biology. 23 (10): 2076–2090. doi: 10.1111/j.1420-9101.2010.02081.x . PMID   20840306.
  7. Quemeneur, Sonia; de Buffrénil, Vivian; Laurin, Michel (2013). "Microanatomy of the amniote femur and inference of lifestyle in limbed vertebrates: Femoral Microanatomy and Lifestyle". Biological Journal of the Linnean Society. 109 (3): 644–655. doi: 10.1111/bij.12066 .