Baphetidae is an extinct family of stem-tetrapods. Baphetids were large labyrinthodont predators of the Late Carboniferous period (Namurian through Westphalian) of Europe. Fragmentary remains from the Early Carboniferous of Canada have been tentatively assigned to the group. The phylogenetic relationships of baphetids is uncertain; while many studies have placed the group as a close relative of Amniota, other analyses have found Baphetidae to be a more basal clade of early stem tetrapods. Baphetids were among the first of the Carboniferous fossil tetrapods to be found and were originally described in 1850 by John William Dawson. The baphetids have been referred to the family Loxommatidae, but this group was later shown to be a junior synonym of Baphetidae, which was named earlier in 1865. Baphetids are known mainly from skulls; very little postcranial material has been found.
The presence of lateral lines and the long rows of needle-like teeth show that most were fish-eaters. Their development was likely amphibian, though no larval fossils are known. Their best-known characteristic was a curious, keyhole-shaped orbit formed by excavation of the lacrimal and prefrontal bones in front of the eye. It has been suggested that this space accommodated a salt gland or some kind of electrosensory organ.[2] Perhaps the better hypothesis is that the space allowed room for the contraction of an enlarged pterygoideus muscle. In that case, this skull modification would represent an early form of skull fenestration for jaw muscles.
The skull is shallow. Unlike the better-known embolomeres, the baphetid cheek and skull roof are sutured together. There is a strongly embayed spiracular ("otic") notch, but the stapes is distally broad, which seems to rule out a sensitive hearing apparatus. The palate is closed—a primitive character, but very different from the temnospondyls. The coronoids bear no teeth or denticles, while the dentary has a double tooth row.
Since the taxon is based almost exclusively on skulls, the body is very poorly known. It is often said that the body was crocodile-like, but this appears to be largely supposition.
It is not clear whether all of the genera assigned to this group are really closely related. The traditional four genera of baphetids (Loxomma, Baphetes, Megalocephalus, and Spathicephalus) have recently been supplemented by Eucritta, a somewhat different form. It has also been suggested that Crassigyrinus may be closely related.
Taxonomyedit
Baphetids were first described by Edward Drinker Cope when he erected the family Baphetidae in 1865 for Baphetes. Richard Lydekker named Loxomatinae in 1889 for Loxomma, which later became known as Loxommatidae. D. M. S. Watson described the group as Loxommidae in 1917. Later studies have shown Baphetes and Loxomma to be close relatives within the same family, and because Baphetidae was named before Loxommatidae, it has seniority and is the valid name of the group.[3]
Phylogenyedit
Baphetids have been previously considered primitive temnospondyls[citation needed] and more recently batrachosaurs (reptile-like amphibia)[citation needed]. It is likely, however, that they represent one more of a number of early Carboniferous tetrapodomorph radiations[citation needed]. Computer-assisted phylogenetic analyses of a data matrix using characteristics of most of the major groups of terrestrial vertebrates place the Baphetids close to the ancestry of amniotes[citation needed].
With the reinterpretation of the Ichthyostegalia as aquatic forms[citation needed], baphetids are good candidates for the spot of first labyrinthodont group to actually spend substantial time on land[citation needed]. If so, baphetids may be a rather important taxon[opinion].
Referencesedit
^Milner, A.C.; Milner, A.R.; Walsh, S.A. (2009). "A new specimen of Baphetes from Nýřany, Czech Republic and the intrinsic relationships of the Baphetidae". Acta Zoologica. 90 (Supplement 1): 318–334. doi:10.1111/j.1463-6395.2008.00340.x.
^Bjerring, H. C. (1986). Electric tetrapods? In: Studies in Herpetology (ed. Z. Rocek), pp. 29–36. Prague: Charles University.
^Milner, A.C.; Lindsay, W. (1998). "Postcranial remains of Baphetes and their bearing on the relationships of the Baphetidae (= Loxommatidae)". Zoological Journal of the Linnean Society. 22 (1): 211–235. doi:10.1111/j.1096-3642.1998.tb02530.x.
January 01, 1970
baphetidae, extinct, family, stem, tetrapods, baphetids, were, large, labyrinthodont, predators, late, carboniferous, period, namurian, through, westphalian, europe, fragmentary, remains, from, early, carboniferous, canada, have, been, tentatively, assigned, g. Baphetidae is an extinct family of stem tetrapods Baphetids were large labyrinthodont predators of the Late Carboniferous period Namurian through Westphalian of Europe Fragmentary remains from the Early Carboniferous of Canada have been tentatively assigned to the group The phylogenetic relationships of baphetids is uncertain while many studies have placed the group as a close relative of Amniota other analyses have found Baphetidae to be a more basal clade of early stem tetrapods Baphetids were among the first of the Carboniferous fossil tetrapods to be found and were originally described in 1850 by John William Dawson The baphetids have been referred to the family Loxommatidae but this group was later shown to be a junior synonym of Baphetidae which was named earlier in 1865 Baphetids are known mainly from skulls very little postcranial material has been found BaphetidsTemporal range 326 307 Ma PreꞒ Ꞓ O S D C P T J K Pg N Late Carboniferous Life restoration of Loxomma Scientific classification Domain Eukaryota Kingdom Animalia Phylum Chordata Clade Sarcopterygii Clade Tetrapodomorpha Superfamily Baphetoidea Family BaphetidaeCope 1865 Subgroups Baphetes Loxommatinae Lydekker 1889 1 Kyrinion Loxomma Megalocephalus Synonyms Loxommatidae Contents 1 Palaeobiology 2 Taxonomy 2 1 Phylogeny 3 ReferencesPalaeobiology editThe presence of lateral lines and the long rows of needle like teeth show that most were fish eaters Their development was likely amphibian though no larval fossils are known Their best known characteristic was a curious keyhole shaped orbit formed by excavation of the lacrimal and prefrontal bones in front of the eye It has been suggested that this space accommodated a salt gland or some kind of electrosensory organ 2 Perhaps the better hypothesis is that the space allowed room for the contraction of an enlarged pterygoideus muscle In that case this skull modification would represent an early form of skull fenestration for jaw muscles The skull is shallow Unlike the better known embolomeres the baphetid cheek and skull roof are sutured together There is a strongly embayed spiracular otic notch but the stapes is distally broad which seems to rule out a sensitive hearing apparatus The palate is closed a primitive character but very different from the temnospondyls The coronoids bear no teeth or denticles while the dentary has a double tooth row Since the taxon is based almost exclusively on skulls the body is very poorly known It is often said that the body was crocodile like but this appears to be largely supposition nbsp Megalocephalus It is not clear whether all of the genera assigned to this group are really closely related The traditional four genera of baphetids Loxomma Baphetes Megalocephalus and Spathicephalus have recently been supplemented by Eucritta a somewhat different form It has also been suggested that Crassigyrinus may be closely related Taxonomy editBaphetids were first described by Edward Drinker Cope when he erected the family Baphetidae in 1865 for Baphetes Richard Lydekker named Loxomatinae in 1889 for Loxomma which later became known as Loxommatidae D M S Watson described the group as Loxommidae in 1917 Later studies have shown Baphetes and Loxomma to be close relatives within the same family and because Baphetidae was named before Loxommatidae it has seniority and is the valid name of the group 3 Phylogeny edit Baphetids have been previously considered primitive temnospondyls citation needed and more recently batrachosaurs reptile like amphibia citation needed It is likely however that they represent one more of a number of early Carboniferous tetrapodomorph radiations citation needed Computer assisted phylogenetic analyses of a data matrix using characteristics of most of the major groups of terrestrial vertebrates place the Baphetids close to the ancestry of amniotes citation needed With the reinterpretation of the Ichthyostegalia as aquatic forms citation needed baphetids are good candidates for the spot of first labyrinthodont group to actually spend substantial time on land citation needed If so baphetids may be a rather important taxon opinion References edit Milner A C Milner A R Walsh S A 2009 A new specimen of Baphetes from Nyrany Czech Republic and the intrinsic relationships of the Baphetidae Acta Zoologica 90 Supplement 1 318 334 doi 10 1111 j 1463 6395 2008 00340 x Bjerring H C 1986 Electric tetrapods In Studies in Herpetology ed Z Rocek pp 29 36 Prague Charles University Milner A C Lindsay W 1998 Postcranial remains of Baphetes and their bearing on the relationships of the Baphetidae Loxommatidae Zoological Journal of the Linnean Society 22 1 211 235 doi 10 1111 j 1096 3642 1998 tb02530 x Retrieved from https en wikipedia org w index php title Baphetidae amp oldid 1215039919, wikipedia, wiki, book, books, library,
