Amphibamidae

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Amphibamidae
Temporal range: Late CarboniferousEarly Triassic, 307–248Ma
Possible descendant taxon Lissamphibia survives to present.
Amphibamus BW.jpg
Amphibamus grandiceps
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: "Amphibia" (wide sense)
Order: Temnospondyli
Superfamily: Dissorophoidea
Family: Amphibamidae
Moodie, 1916
Synonyms
  • Doleserpetontidae Bolt, 1969

Amphibamidae is an extinct family of dissorophoid euskelian temnospondyls. The earliest amphibamids, such as Amphibamus, are known from Late Carboniferous strata in the United States[1] and the Czech Republic,[2] while the last known amphibamid, Micropholis, is known from the Early Triassic Karoo Basin of South Africa. According to some phylogenetic studies, modern amphibians, including frogs, salamanders, and caecilians, may have descended from a common ancestor that was an amphibamid.

Classification[edit]

Cladogram from Schoch and Rubidge (2005):[3]

Amphibamidae 

Micropholis




Eoscopus




Platyrhinops




Doleserpeton



Amphibamus






Cladogram from Huttenlocker et al. (2007):[4]

Amphibamidae 


Platyrhinops




Amphibamus



Doleserpeton






Eoscopus




"Tersomius" mosesi




"Tersomius" sp.




Plemmyradytes



Micropholis







Cladogram from Fröbisch and Reisz (2008):[5]

Amphibamidae 


Georgenthalia




Eoscopus




Plemmyradytes




Platyrhinops




Doleserpeton




Gerobatrachus



Amphibamus










Tersomius




Micropholis



Pasawioops





Relationship to Batrachia[edit]

Amphibamidae contains the genus Gerobatrachus, which has been interpreted as the sister taxon of Batrachia, the modern amphibians.[6] This would make Amphibamidae a paraphyletic taxon, since it would not contain all descendants of the last common ancestor of amphibamids. If Gerobatrachus is the sister taxon of Batrachia, then all modern amphibians descend from an amphibamid ancestor. Below is a modified cladogram from Anderson et al. (2008) showing Batrachia nested in Amphibamidae, with Gerobatrachus as the sister taxon of Batrachia:[6]

Amphibamidae 


Tersomius



Micropholis





Eoscopus




Platyrhinops




Amphibamus




Doleserpeton




Gerobatrachus


 Batrachia 


Anura



Triadobatrachus





Caudata



Albanerpetontidae










The cladistic analysis of Anderson et al. (2008) supported the "polyphyly hypothesis" of modern amphibian ancestry, whereby some extant amphibian groups are descendants of temnospondyls while others are descendants of lepospondyls, another large group of Paleozoic amphibians.[7] Caecilians were nested within Lepospondyli, making Lissamphibia polyphyletic. However, the placement of Batrachia within Amphibamidae has been controversial, and alternate hypotheses of lissamphibian ancestry remain. Some authors of more recent studies have suggested that the findings of Anderson et al. (2008) may be wrong, and that lissamphibians are descendants of lepospondyls.[7] This would make Amphibamidae a monophyletic grouping much more distantly related to lissamphibians.

References[edit]

  1. ^ Gaining Ground: The Origin and Early Evolution of Tetrapods by Jennifer A. Clack
  2. ^ Andrew R. Milner and Sandra E.K. Sequeira (2003). "Revision of the amphibian genus Limnerpeton (Temnospondyli) from the Upper Carboniferous of the Czech Republic". Acta Palaeontologica Polonica 48 (1): 123–141. 
  3. ^ Schoch, R.R.; Rubidge, B.S. (2005). "The amphibamid Micropholis from the Lystrosaurus Assemblage Zone of South Africa". Journal of Vertebrate Paleontology 25 (3): 502–522. doi:10.1671/0272-4634(2005)025[0502:TAMFTL]2.0.CO;2. 
  4. ^ Huttenlocker, A.K.; Pardo, J.D.; Small, B.J. (2007). "Plemmyradytes shintoni, gen. et. sp. nov., an Early Permian Amphibamid (Temnospondyli:Dissorophoidea) from the Eskridge Formation, Nebraska". Journal of Vertebrate Paleontology 27 (2): 316–328. doi:10.1671/0272-4634(2007)27[316:PSGESN]2.0.CO;2. 
  5. ^ Fröbisch, N.B.; Reisz, R.R. (2008). "A new Lower Permian amphibamid (Dissorophoidea, Temnospondyli) from the fissure fill deposits near Richards Spur, Oklahoma". Journal of Vertebrate Paleontology 28 (4): 1015–1030. doi:10.1671/0272-4634-28.4.1015. 
  6. ^ a b Anderson, J.S.; Reisz, R.R.; Scott, D.; Fröbisch, N.B.; Sumida, S.S. (2008). "A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders". Nature 453 (7194): 515–518. doi:10.1038/nature06865. PMID 18497824. 
  7. ^ a b Marjanović, D.; Laurin, M. (2009). "A closer look at published data matrices reveals support for the "lepospondyl hypothesis" on the origin of Lissamphibia". Abstracts from the 7th Annual Meeting of the European Association of Vertebrate Palaeontologists: 45. 

External links[edit]