Eucritta melanolimnetes from the Early Carboniferous of Scotland, a stem tetrapod showing a mosaic of characteristics

Author(s):  
J. A. Clack

The stem tetrapod Eucritta melanolimnetes is described in full from five specimens. The animal is compared in detail with the contemporary and superficially similar temnospondyl Balanerpeton woodi, and with baphetids (=loxommatids). Growth of Eucritta skulls approaches isometry, and lies on the same trajectory as skulls belonging to the genus Baphetes. The function of the temporal embayment is discussed; it was probably not associated with an air-borne hearing device. The axial skeleton of Eucritta was ossified in larger specimens. Ribs in Eucritta gain expanded distal ends with growth, and the animal probably breathed by buccal pumping. An updated cladistic analysis is presented, incorporating data from a fifth specimen. Eucritta remains as a probable basal baphetid, but the sister group to the baphetids remains uncertain.

2013 ◽  
Vol 27 (1) ◽  
pp. 129
Author(s):  
Edilson Caron ◽  
Cibele S. Ribeiro-Costa ◽  
Alfred F. Newton

Rove beetles of the genus Piestus Gravenhorst, 1806 are commonly captured under the bark of or inside decaying logs from Neotropical forests. Piestus belongs to the subfamily Piestinae, historically an ill-defined dumping-ground for Staphylinidae defined by plesiomorphic characters, but which has gradually been restricted in concept and currently includes only six additional extant genera worldwide. Piestinae in this restricted sense has been considered a probably monophyletic subfamily, but its status and phylogenetic position, as a possible sister-group of Osoriinae within the recently proposed Oxyteline group of staphylinid subfamilies, are uncertain and need confirmation. The main aim of the present study was to provide a morphological cladistic analysis and complete taxonomic revision of Piestus, which, as the type and most speciose genus of Piestinae, is critical for future phylogenetic studies involving the subfamily. In our study, the monophyly of Piestus is established and phylogenetic relationships among its species are proposed based on 70 adult morphological characters. Piestus is supported by 11 synapomorphies and high branch support. All species of Piestus are revised and the genus is redefined. The genus contains 43 species, including 13 species described here for the first time. The previously proposed subgenera Antropiestus Bernhauer, 1917, Eccoptopiestus Scheerpeltz, 1952, Elytropiestus Scheerpeltz, 1952, Lissopiestus Scheerpeltz, 1952, Piestus s. str., Trachypiestus Scheerpeltz, 1952 and Zirophorus Dalman, 1821 have not been confirmed, as they were found to be poly- or paraphyletic, or are here removed from Piestus, and therefore subgenera are not used. The main taxonomic changes are as follows. Lissopiestus, syn. nov. is proposed as new synonym of Eleusis Laporte, 1835 and its species, E. interrupta (Erichson, 1840), comb. rest., is transferred again to that genus. Antropiestus, syn. nov. and Eccoptopiestus, syn. nov. are proposed as new synonyms of Hypotelus Erichson, 1839 and their species, H. laevis (Solsky, 1872), comb. nov. and H. andinus (Bernhauer, 1917), comb. nov., are transferred to Hypotelus. Fourteen new synonymies are proposed (valid species listed first): P. lacordairei Laporte, 1835 = Z. furcatus Sharp, 1887, syn. nov.; P. capricornis Laporte, 1835 = P. frontalis Sharp, 1876, syn. nov.; P. pennicornis Fauvel, 1864 = P. plagiatus Fauvel, 1864, syn. nov.; P. rectus Sharp, 1876, syn. nov.; P. pygialis Fauvel, 1902, syn. nov.; P. surinamensis Bernhauer, 1928, syn. nov.; P. minutus Erichson, 1840 = P. nigrator Fauvel, 1902, syn. nov.; P. sulcatus Gravenhorst, 1806 = P. sanctaecatharinae Bernhauer, 1906, syn. nov.; P. condei Wendeler, 1955, syn. nov.; P. gounellei Fauvel, 1902 = P. wasmanni Fauvel, 1902, syn. nov.; P. mexicanus Laporte, 1835 = P. alternans Sharp, 1887, syn. nov.; P. aper Sharp, 1876 = P. schadei Scheerpeltz, 1952, syn. nov.; P. angularis Fauvel, 1864 = P. crassicornis Sharp, 1887, syn. nov.; H. andinus (Bernhauer, 1917) = P. strigipennis Bernhauer, 1921, syn. nov. One species is revalidated: P. fronticornis (Dalman, 1821), stat. rev., and one synonym is restored: P. penicillatus (Dalman, 1821) = P. erythropus Erichson, 1840, syn. rest. Neotypes are designated for P. lacordairei Laporte, 1835 and Oxytelus bicornis Olivier, 1811, and lectotypes are designated for P. puncticollis Fauvel, 1902, P. capricornis variety muticus Fauvel, 1902, P. zischkai Scheerpeltz, 1951, P. pennicornis Fauvel, 1864, P. plagiatus Fauvel, 1864, P. pygmaeus Laporte, 1835, P. niger Fauvel 1864, P. minutus Erichson, 1840, P. nigratror Fauvel, 1902, P. sulcatus Gravenhorst, 1806, P. sanctaecatharinae Bernhauer, 1906, P. sulcipennis Scheerpeltz, 1952, P. aper Sharp, 1876, P. schadei Scheerpeltz, 1952 and P. andinus Bernhauer, 1917.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12597
Author(s):  
Alice M. Clement ◽  
Richard Cloutier ◽  
Jing Lu ◽  
Egon Perilli ◽  
Anton Maksimenko ◽  
...  

Background The megalichthyids are one of several clades of extinct tetrapodomorph fish that lived throughout the Devonian–Permian periods. They are advanced “osteolepidid-grade” fishes that lived in freshwater swamp and lake environments, with some taxa growing to very large sizes. They bear cosmine-covered bones and a large premaxillary tusk that lies lingually to a row of small teeth. Diagnosis of the family remains controversial with various authors revising it several times in recent works. There are fewer than 10 genera known globally, and only one member definitively identified from Gondwana. Cladarosymblema narrienense Fox et al. 1995 was described from the Lower Carboniferous Raymond Formation in Queensland, Australia, on the basis of several well-preserved specimens. Despite this detailed work, several aspects of its anatomy remain undescribed. Methods Two especially well-preserved 3D fossils of Cladarosymblema narrienense, including the holotype specimen, are scanned using synchrotron or micro-computed tomography (µCT), and 3D modelled using specialist segmentation and visualisation software. New anatomical detail, in particular internal anatomy, is revealed for the first time in this taxon. A novel phylogenetic matrix, adapted from other recent work on tetrapodomorphs, is used to clarify the interrelationships of the megalichthyids and confirm the phylogenetic position of C. narrienense. Results Never before seen morphological details of the palate, hyoid arch, basibranchial skeleton, pectoral girdle and axial skeleton are revealed and described. Several additional features are confirmed or updated from the original description. Moreover, the first full, virtual cranial endocast of any tetrapodomorph fish is presented and described, giving insight into the early neural adaptations in this group. Phylogenetic analysis confirms the monophyly of the Megalichthyidae with seven genera included (Askerichthys, Cladarosymblema, Ectosteorhachis, Mahalalepis, Megalichthys, Palatinichthys, and Sengoerichthys). The position of the megalichthyids as sister group to canowindrids, crownward of “osteolepidids” (e.g.,Osteolepis and Gogonasus), but below “tristichopterids” such as Eusthenopteron is confirmed, but our findings suggest further work is required to resolve megalichthyid interrelationships.


1992 ◽  
Vol 335 (1274) ◽  
pp. 207-219 ◽  

Sphenodon has traditionally been regarded as a little changed survivor of the Permo-Triassic thecodont or eosuchian ‘stem reptiles’ but has alternatively been placed in the Lepidosauria as the plesiomorphic or even apomorphic sister-taxon of the squamates. A cladistic analysis of 16 characters from spermatozoal ultrastructure of Sphenodon and other amniotes unequivocally confirms its exceedingly primitive status. The analysis suggests that monotremes are the sister-group of birds; squamates form the sister-group of a bird + monotreme clade while the three sister-groups successively below the bird + monotreme + squa- mate assemblage are the caiman, the tuatara and the outgroup (turtles). The monotreme + bird couplet, supports the concept of the Haemothermia, but can only be regarded heuristically. The usual concept of mammals as a synapsid-derived outgroup of all other extant amniotes is not substantiated spermatologically. All cladistic analyses made, and a separate consideration of apomorphies, indicate that Sphenodon is spermatologically the most primitive amniote, excepting the Chelonia. It is advanced (apomorphic) for the amniotes in only two of the 16 spermatozoal characters considered. A close, sister-group relationship of Sphenodon with squamates is not endorsed.


Zootaxa ◽  
2005 ◽  
Vol 835 (1) ◽  
pp. 1
Author(s):  
ALEXANDRE B. BONALDO ◽  
ANTONIO D. BRESCOVIT ◽  
CRISTINA A. RHEIMS

A fourth species of Ericaella, E. florezi n. sp., is described based on males and a female from Cauca, Colombia. A cladistic analysis of all known species of Ericaella, plus two outgroup species (Radulphius camacan Bonaldo and Eutichurus luridus Simon) is presented. The single optimal tree obtained depicted a sister group relationship between Ericaella longipes Chickering plus E. florezi sp. n. and E. samiria Bonaldo plus E. kaxinawa Bonaldo.


2002 ◽  
Vol 80 (11) ◽  
pp. 1887-1899 ◽  
Author(s):  
Alison M Murray ◽  
Kathlyn M Stewart

The family Alestidae (also referred to as the African Characidae) comprises the African dwarf forms ("Petersiini") and the genera Alestes, Brycinus, Bryconaethiops, and Hydrocynus. Although several authors have presented characters to support the monophyly of the family, a cladistic analysis of the group has not been published. Furthermore, the interrelationships of the constituent groups are the subject of some controversy. A cladistic analysis of the Alestidae is presented, including characters to support the monophyly of the family. The results of this study indicate that several species should be removed from the genus Brycinus, that Hydrocynus is the sister group of Alestes s.str. (containing only five species), and that the dwarf alestids ("Petersiini") do not form a monophyletic group.


2003 ◽  
Vol 17 (3) ◽  
pp. 387 ◽  
Author(s):  
Gonzalo Giribet

Examination of museum specimens belonging to the cyphophthalmid Gondwanan family Pettalidae has rendered a collection of specimens placed in the new genus Karripurcellia. The genus includes three species, K.�peckorum, sp. nov., K. sierwaldae, sp. nov. and K. harveyi, sp. nov., from the Pemberton area in Western Australia. These are the first cyphophthalmid species found outside Queensland in Australia. Karripurcellia, gen. nov. is distinguished from other Australian pettalids by the lack of modifications in the anal plate, as well as the lack of the typical male anal glands of pettalids, sironids and the stylocellid genus Fangensis Rambla, 1994. Two of the species, K. peckorum, sp. nov. and K. sierwaldae, sp. nov., live sympatrically and have been collected in the same litter samples in one locality. The proposition of the new genus is accompanied by a cladistic analysis of all pettalid genera and most species within each genus, with the exception of the species-rich genus Rakaia Hirst, 1925. The cladistic analysis supports the monophyly of the Karripurcellia, gen. nov. species, but their sister-group relationships are unclear. However, the remaining Australian species cluster with the pettalids from New Zealand and South Africa, but not with Karripurcellia, sp. nov.


2019 ◽  
Vol 6 (5) ◽  
pp. 182087 ◽  
Author(s):  
Jennifer A. Clack ◽  
Marcello Ruta ◽  
Andrew R. Milner ◽  
John E. A. Marshall ◽  
Timothy R. Smithson ◽  
...  

The enigmatic tetrapod Acherontiscus caledoniae from the Pendleian stage of the Early Carboniferous shows heterodontous and durophagous teeth, representing the earliest known examples of significant adaptations in tetrapod dental morphology. Tetrapods of the Late Devonian and Early Carboniferous (Mississippian), now known in some depth, are generally conservative in their dentition and body morphologies. Their teeth are simple and uniform, being cone-like and sometimes recurved at the tip. Modifications such as keels occur for the first time in Early Carboniferous Tournaisian tetrapods. Acherontiscus , dated as from the Pendleian stage, is notable for being very small with a skull length of about 15 mm, having an elongate vertebral column and being limbless. Cladistic analysis places it close to the Early Carboniferous adelospondyls, aïstopods and colosteids and supports the hypothesis of ‘lepospondyl’ polyphyly. Heterodonty is associated with a varied diet in tetrapods, while durophagy suggests a diet that includes hard tissue such as chitin or shells. The mid-Carboniferous saw a significant increase in morphological innovation among tetrapods, with an expanded diversity of body forms, skull shapes and dentitions appearing for the first time.


Zootaxa ◽  
2010 ◽  
Vol 2425 (1) ◽  
pp. 45 ◽  
Author(s):  
ÂNGELO PARISE PINTO ◽  
ALCIMAR DO LAGO CARVALHO

Lauromacromia melanica sp. nov. from Conceição da Barra municipality, Espírito Santo State, Brazil, is described and illustrated based on two males (both in MNRJ nº 135). The new species is similar to L. picinguaba differing from it mainly by the absence of pale spots on S3–6 and by the ellipsoid shape of metepisternal pale stripe. A key for males of all species of the genus is provided. A cladistic analysis encompassing 43 external morphological male characters carried out in two distinct procedures, the first with all characters unordered and the second with two or three state characters ordered. The unordered analysis generated only one most-parsimonious tree (66 steps of length, CI = 0.69, RI = 0.62). The hypothesis of monophyly of Lauromacromia is supported and includes three groups, one formed by the Atlantic Forest species (L. melanica sp. nov. + L. picinguaba), and another by the Cerrado species (L. flaviae + (L. bedei + L. luismoojeni)), and L. dubitalis, positioned in polytomy with these two groups. The ordered analysis also generated only one most-parsimonious tree (68 steps of length, CI = 0.70, RI = 0.67), which maintained the monophyly of Lauromacromia but L. dubitalis positioned basally as sister-group to the Atlantic Forest + Cerrado species groups. The geographic distribution of Lauromacromia is updated with a new record of L. luismoojeni based on one adult male (Brazil: Mato Grosso do Sul State) and probable first Brazilian records for L. dubitalis (Amazonas and Pará States) based on two larvae. A vicariance hypothesis is proposed to explain spatial evolution of Lauromacromia, and based on current biogeographical classifications we consider Gomphomacromia and Rialla apart from Neotropical biota. Some aspects of biology and ecology of Lauromacromia are also discussed.


Author(s):  
Jozef Klembara ◽  
Marcello Ruta

ABSTRACTThe postcranial skeleton of Ariekanerpeton sigalovi (Seymouriamorpha: Discosauriscidae; Lower Permian, Tadzhikistan) differs from that of like-sized Discosauriscus specimens in showing: wider interclavicle anterior plate with smaller, rhomboidal sculptured field on its ventral surface not reaching plate posteromedial margins; broader interclavicle plate-stem junction; slightly narrower interclavicle posterior stem; anteroposteriorly narrower clavicle ventral plate with convex posterior margin; shorter, more robust humerus; four phalanges on fourth manus digit (five phalanges in Discosauriscus); ilium more elongate dorsoventrally with anteroposteriorly narrower neck; posterior process of iliac blade oriented distinctly posterodorsally rather than horizontally; more gracile atlantal rib; broadened distal end of second presacral rib. A revised cladistic analysis of the best known seymouriamorph species retrieves Ariekanerpeton either as sister group to both species of Discosauriscus, or to D. austriacus only.


2020 ◽  
pp. 1-45
Author(s):  
Bruno Zilberman

Corotoca is a strictly Neotropical genus of termitophilous beetles associated with termites of genus Constrictotermes. A cladistic analysis based on 13 terminal taxa and 60 characters (57 morphological and three behavioral) was conducted. The exhaustive search with equally weighted characters resulted in two most parsimonious trees with 95 steps. Spirachtha is proposed to be the sister group of the monophyletic “subgroup Corotocae” (Corotoca + Cavifonexus gen. nov.), based on eleven synapomorhphies (ten exclusive and one homoplastic). The monophyly of Corotoca is supported here, including six species associated with Constrictotermes cyphergaster: (Corotoca hitchensi sp. nov + (C. melantho + C. pseudomelantho sp. nov.) + ((C. fontesi + (C. phylo + C. araujoi)). A new genus, Cavifronexus gen. nov., is proposed to two species associated with Constrictotermes cavifrons (Holmgren, 1910): Cavifronexus guyanae comb. nov., from Guyana and Brazil, previously described as Corotoca; and a new species, Cavifronexus papaveroi sp. nov., from Brazil. This work also includes descriptions, redescriptions, and illustrations for all species and genera. Keys for genera and species identification in “subgroup Corotocae” are also provided.


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