scholarly journals A new Early Permian reptile and its significance in early diapsid evolution

2011 ◽  
Vol 278 (1725) ◽  
pp. 3731-3737 ◽  
Author(s):  
Robert R. Reisz ◽  
Sean P. Modesto ◽  
Diane M. Scott
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Sedimentary Rocks ◽  
Sister Group ◽  
Flood Plain ◽  
Middle Permian ◽  
Lower Permian ◽  
Early Permian ◽  
Terrestrial Vertebrate

The initial stages of evolution of Diapsida (the large clade that includes not only snakes, lizards, crocodiles and birds, but also dinosaurs and numerous other extinct taxa) is clouded by an exceedingly poor Palaeozoic fossil record. Previous studies had indicated a 38 Myr gap between the first appearance of the oldest diapsid clade (Araeoscelidia), ca 304 million years ago (Ma), and that of its sister group in the Middle Permian ( ca 266 Ma). Two new reptile skulls from the Richards Spur locality, Lower Permian of Oklahoma, represent a new diapsid reptile: Orovenator mayorum n. gen. et sp. A phylogenetic analysis identifies O. mayorum as the oldest and most basal member of the araeoscelidian sister group. As Richards Spur has recently been dated to 289 Ma, the new diapsid neatly spans the above gap by appearing 15 Myr after the origin of Diapsida. The presence of O. mayorum at Richards Spur, which records a diverse upland fauna, suggests that initial stages in the evolution of non-araeoscelidian diapsids may have been tied to upland environments. This hypothesis is consonant with the overall scant record for non-araeoscelidian diapsids during the Permian Period, when the well-known terrestrial vertebrate communities are preserved almost exclusively in lowland deltaic, flood plain and lacustrine sedimentary rocks.

scholarly journals Olson's Extinction and the latitudinal biodiversity gradient of tetrapods in the Permian

2017 ◽  
Vol 284 (1852) ◽  
pp. 20170231 ◽  
Author(s):  
Neil Brocklehurst ◽  
Michael O. Day ◽  
Bruce S. Rubidge ◽  
Jörg Fröbisch
Keyword(s):  
North America ◽  
Mass Extinction ◽  
Fossil Record ◽  
Middle Permian ◽  
Lower Permian ◽  
Vertebrate Fauna ◽  
Terrestrial Vertebrate ◽  
Substantial Change

The terrestrial vertebrate fauna underwent a substantial change in composition between the lower and middle Permian. The lower Permian fauna was characterized by diverse and abundant amphibians and pelycosaurian-grade synapsids. During the middle Permian, a therapsid-dominated fauna, containing a diverse array of parareptiles and a considerably reduced richness of amphibians, replaced this. However, it is debated whether the transition is a genuine event, accompanied by a mass extinction, or whether it is merely an artefact of the shift in sampling from the palaeoequatorial latitudes to the palaeotemperate latitudes. Here we use an up-to-date biostratigraphy and incorporate recent discoveries to thoroughly review the Permian tetrapod fossil record. We suggest that the faunal transition represents a genuine event; the lower Permian temperate faunas are more similar to lower Permian equatorial faunas than middle Permian temperate faunas. The transition was not consistent across latitudes; the turnover occurred more rapidly in Russia, but was delayed in North America. The argument that the mass extinction is an artefact of a latitudinal biodiversity gradient and a shift in sampling localities is rejected: sampling correction demonstrates an inverse latitudinal biodiversity gradient was prevalent during the Permian, with peak diversity in the temperate latitudes.

scholarly journals A small caseid synapsid, Arisierpeton simplex gen. et sp. nov., from the early Permian of Oklahoma, with a discussion of synapsid diversity at the classic Richards Spur locality

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6615 ◽  
Author(s):  
Robert R. Reisz
Keyword(s):  
North America ◽  
Fossil Record ◽  
Middle Permian ◽  
Lower Permian ◽  
Early Permian ◽  
Faunal Assemblage ◽  
Lower Jaw ◽  
Continental Deposits ◽  
Faunal List ◽  
Taxic Diversity

The fossil record of caseids, a clade of faunivorous to large herbivorous Permian synapsids, is unusual in having a poorly documented history. Although Kungurian caseids are common in the well-known continental deposits of North America, and the fossil record of the group extends into the middle Permian (Guadalupian), with the presence of the large caseid Ennatosaurus in the Mezen Basin faunal assemblage, only two other occurrences are known in older Permian age sediments. One is an undescribed caseid from the Bromacker Quarry in Germany, and the second is Oromycter from the lower Permian of Richards Spur, Oklahoma. The former is known from several articulated skeletons, but the latter is known only from a handful of skeletal elements, including elements of the snout and lower jaw, some phalanges, and a few vertebrae. Here the fragmentary tooth bearing elements and dorsal vertebrae of another small caseid from Richards Spur are described, with a discussion of its significance in the context of caseid evolution, and the continuously expanding faunal list and taxic diversity at this locality.

scholarly journals The oldest peracarid crustacean reveals a Late Devonian freshwater colonization by isopod relatives

2021 ◽  
Vol 17 (6) ◽  
pp. 20210226
Author(s):  
N. Robin ◽  
P. Gueriau ◽  
J. Luque ◽  
D. Jarvis ◽  
A. C. Daley ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Sister Group ◽  
Two Dimensions ◽  
Late Devonian ◽  
Digital Microscopy ◽  
Single Specimen ◽  
Terrestrial Environments ◽  
Anatomical Characters

Peracarida (e.g. woodlice and side-swimmers) are, together with their sister-group Eucarida (e.g. krill and decapods), the most speciose group of modern crustaceans, suggested to have appeared as early as the Ordovician. While eucarids' incursion onto land consists of mainly freshwater and littoral grounds, some peracarids have evolved fully terrestrial ground-crawling ecologies, inhabiting even our gardens in temperate regions (e.g. pillbugs and sowbugs). Their fossil record extends back to the Carboniferous and consists mainly of marine occurrences. Here, we provide a complete re-analysis of a fossil arthropod— Oxyuropoda— reported in 1908 from the Late Devonian floodplains of Ireland, and left with unresolved systematic affinities despite a century of attempts at identification. Known from a single specimen preserved in two dimensions, we analysed its anatomy using digital microscopy and multispectral macroimaging to enhance the contrast of morphological structures. The new anatomical characters and completeness of Oxyuropoda , together with a phylogenetic analysis with representatives of all major Eumalacostraca groups, indicate that Oxyuropoda is a crown peracarid, part of a clade including amphipods and isopods. As such, Oxyuropoda is the oldest known species Peracarida, and provides evidence that derived peracarids had an incursion into freshwater and terrestrial environments as early as the Famennian, more than 360 Ma.

scholarly journals The oldest peracarid crustacean reveals a Late Devonian freshwater colonisation by isopod relatives

2021 ◽  
Author(s):  
Ninon Robin ◽  
Pierre Gueriau ◽  
Javier Luque ◽  
David Jarvis ◽  
Allison Daley ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
Sister Group ◽  
Two Dimensions ◽  
Late Devonian ◽  
Digital Microscopy ◽  
Single Specimen ◽  
Terrestrial Environments ◽  
Anatomical Characters

Peracarida (e.g., woodlice & side-swimmers) are, together with their sister-group Eucarida (e.g. krill & decapods), the most speciose group of modern crustaceans, suggested to have appeared as early as the Ordovician. While eucarids incursion onto land consists of mainly freshwater and littoral grounds, some peracarids have evolved fully terrestrial ground-crawling ecologies, inhabiting even our gardens in temperate regions (e.g. pillbugs and sowbugs). Their fossil record extends back to the Carboniferous and consists mainly of marine occurrences. Here, we provide a complete re-analysis of a fossil arthropod, Oxyuropoda, reported in 1908 from the Late Devonian floodplains of Ireland, and left with unresolved systematic affinities despite a century of attempts at identification. Known from a single specimen preserved in two-dimensions, we analysed its anatomy using digital microscopy and multispectral macro-imaging to enhance contrast of morphological structures. The new anatomical characters and completeness of Oxyuropoda, together with a phylogenetic analysis with representatives of all major Eumalacostraca groups, indicate that Oxyuropoda is a crown-peracarid, part of a clade including amphipods and isopods. As such, Oxyuropoda is the oldest known Peracarida, and provides evidence that derived peracarids had an incursion into freshwater and terrestrial environments as early as the Famennian, more than 360 million years ago.

Archaeovenator hamiltonensis, a new varanopid (Synapsida: Eupelycosauria) from the Upper Carboniferous of Kansas

2003 ◽  
Vol 40 (4) ◽  
pp. 667-678 ◽  
Author(s):  
Robert R Reisz ◽  
David W Dilkes
Keyword(s):  
Phylogenetic Analysis ◽  
Fossil Record ◽  
New Genus ◽  
Late Carboniferous ◽  
Middle Permian ◽  
Sister Taxon ◽  
New Genus And Species ◽  
Upper Carboniferous ◽  
Carboniferous Limestone

Study of a nearly complete skeleton of a small amniote, preserved as part and counterpart in Upper Carboniferous limestone slabs of the Hamilton Quarry, Kansas, indicates that it is a new genus and species of varanopid synapsid. Archaeovenator hamiltonensis gen., and sp. nov. is the oldest known varanopid. Phylogenetic analysis indicates that it is the sister taxon to all other known varanopids. Discovery of this new varanopid is important because it improves our knowledge of the terrestrial fauna of the Hamilton quarry, expands the known diversity of Late Carboniferous basal synapsids, and extends the fossil record of Varanopidae deeper within the Stephanian. Varanopidae has the longest fossil record (Late Carboniferous – upper Middle Permian) of all known clades of basal synapsids.

Re-evaluation of an early sphenacodontian synapsid from the Lower Permian of England

2019 ◽  
Vol 111 (1) ◽  
pp. 27-37 ◽  
Author(s):  
Frederik SPINDLER
Keyword(s):  
Fossil Record ◽  
Ecological Model ◽  
Lower Permian ◽  
New Taxon ◽  
Early Permian ◽  
Tolerance Range ◽  
Environmental Tolerance ◽  
Unique Character ◽  
Mosaic Distribution

ABSTRACTThe holotypic isolated maxilla of the early sphenacodontian Haptodus grandis from the Cisuralian of England is revisited. A unique character combination includes haptodontine-grade traits like less specialised teeth and a high number of precanines, but at the same time a shortened lacrimal that is separated from the naris, which is strongly diagnostic of Sphenacodontoidea. As the specimen cannot be assigned to any known taxon, the new taxon Hypselohaptodus grandis gen. nov. is proposed. Comparison with other sphenacodontians reveals a mosaic distribution of maxillary features, most significantly regarding the precanine region. Preliminary character histories preclude Hypselohaptodus from Sphenacodontidae, but suggest a haptodontine-grade or basal therapsid position. The latter hypothesis is substantiated by an ecological model of episodic wet phases in an overall trend of aridification throughout the Permian, to explain the rareness of non-sphenacodontid sphenacodontians in the fossil record. Also from the early Permian of England, an isolated dentary has previously been assigned to Ophiacodon, but can be shown to be either a sphenacodontian, possibly affiliated with Hypselohaptodus, or a robust, Stereorhachis-like ophiacodontid. The absence of Ophiacodon in the intramontaneous Permian basis of Europe is explained by a narrow environmental tolerance range requiring limnic connection with lowland basins.

scholarly journals Canadia spinosa and the early evolution of the annelid nervous system

2019 ◽  
Vol 5 (9) ◽  
pp. eaax5858 ◽  
Author(s):  
Luke Parry ◽  
Jean-Bernard Caron
Keyword(s):  
Phylogenetic Analysis ◽  
Nervous System ◽  
Fossil Record ◽  
Morphological Diversity ◽  
Sister Group ◽  
Early Evolution ◽  
Phylogenetic Position ◽  
Early Cambrian ◽  
Burgess Shale ◽  
Rapid Diversification

Annelid worms are a disparate, primitively segmented clade of bilaterians that first appear during the early Cambrian Period. Reconstructing their early evolution is complicated by the extreme morphological diversity in early diverging lineages, rapid diversification, and sparse fossil record. Canadia spinosa, a Burgess Shale fossil polychaete, is redescribed as having palps with feeding grooves, a dorsal median antenna and biramous parapodia associated with the head and flanking a ventral mouth. Carbonaceously preserved features are identified as a terminal brain, circumoral connectives, a midventral ganglionated nerve cord and prominent parapodial nerves. Phylogenetic analysis recovers neuroanatomically simple extant taxa as the sister group of other annelids, but the phylogenetic position of Canadia suggests that the annelid ancestor was reasonably complex neuroanatomically and that reduction of the nervous system occurred several times independently in the subsequent 500 million years of annelid evolution.

scholarly journals A new species of baenid turtle from the Early Cretaceous Lakota Formation of South Dakota

Fossil Record ◽  
2020 ◽  
Vol 23 (1) ◽  
pp. 1-13
Author(s):  
Walter G. Joyce ◽  
Yann Rollot ◽  
Richard L. Cifelli
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
South Dakota ◽  
Early Cretaceous ◽  
Fossil Record ◽  
Late Jurassic ◽  
Sister Group ◽  
Sister Group Relationship ◽  
Relationship Of ◽  
A New Species

Abstract. Baenidae is a clade of paracryptodiran turtles known from the late Early Cretaceous to Eocene of North America. The proposed sister-group relationship of Baenidae to Pleurosternidae, a group of turtles known from sediments dated as early as the Late Jurassic, suggests a ghost lineage that crosses the early Early Cretaceous. We here document a new species of paracryptodiran turtle, Lakotemys australodakotensis gen. and sp. nov., from the Early Cretaceous (Berriasian to Valanginian) Lakota Formation of South Dakota based on a poorly preserved skull and two partial shells. Lakotemys australodakotensis is most readily distinguished from all other named Late Jurassic to Early Cretaceous paracryptodires by having a broad, baenid-like skull with expanded triturating surfaces and a finely textured shell with a large suprapygal I that laterally contacts peripheral X and XI and an irregularly shaped vertebral V that does not lap onto neural VIII and that forms two anterolateral processes that partially separate the vertebral IV from contacting pleural IV. A phylogenetic analysis suggests that Lakotemys australodakotensis is a baenid, thereby partially closing the previously noted gap in the fossil record.

The fossil record of Phasmida (Insecta: Neoptera)

2000 ◽  
Vol 31 (4) ◽  
pp. 473-480 ◽  
Author(s):  
Erich Tilgner
Keyword(s):  
Dominican Republic ◽  
Molecular Clock ◽  
Fossil Record ◽  
Sister Group ◽  
Baltic Amber ◽  
Molecular Clock Dating

AbstractA review of the Phasmida fossil record is provided. No fossils of Timema Scudder are known. Euphasmida fossils include: Agathemera reclusa Scudder, Electrobaculum gracilis Sharov, Eophasma oregonense Sellick, Eophasma minor Sellick, Eophasmina manchesteri Sellick, Pseudoperla gracilipes Pictet, Pseudoperla lineata Pictet and various unclassified species from Grube Messel, Baltic amber, and Dominican Republic amber. The oldest documented Euphasmida fossils are 44-49 million years old; molecular clock dating underestimates the origin of the sister group Timema by at least 24 million years.

scholarly journals Comparing phylogenetics and linear morphometrics to solve the generic assignment ofParabolinella?triarthroidesHarrington (Trilobita, Olenidae)

2017 ◽  
Vol 91 (5) ◽  
pp. 919-932 ◽  
Author(s):  
Daniela S. Monti ◽  
Viviana A. Confalonieri
Keyword(s):  
Phylogenetic Analysis ◽  
Morphological Traits ◽  
Good Description ◽  
Sister Group ◽  
Integrative Approach ◽  
Original Matrix ◽  
Quantitative Characters ◽  
Phylogenetic Framework ◽  
Methodological Approaches ◽  
Source Of Information

AbstractThe use of different methodological approaches together with an exhaustive qualitative study has helped to recognize important morphological traits to distinguish species in a systematic and phylogenetic framework.Parabolinella triarthroidesHarrington, 1938 was described based on two cranidia from the Quebrada de Coquena, Purmamarca, Jujuy province. The generic assignment ofP. triarthroideshas been questioned by a phylogenetic analysis, which resolves this species as the sister group ofBienvilliaClark, 1924. To explore the generic assignment of this species, a revision of the type material, plus a morphometric analysis including specimens ofParabolinellaBrøgger, 1882 andBienvilliawere performed. In addition, the original matrix used in the published phylogeny was reviewed and enlarged, including more species ofBienvillia. Continuous characters were coded in different ways in order to compare how they could affect the ordering of specimens and their phylogenetic relationships. Finally, both methodologies were compared, especially in regard to the behavior of the quantitative characters included in the analyses. From the combined analyses, it is shown that similarities between the cranidium ofP. triarthroidesand all otherParabolinellaspecies are true homologies instead of a by-product of evolutionary convergence. Therefore,P. triarthroidesshould be considered a member of this genus. Finally, this study demonstrates that the best strategy for solving systematic problems in groups where the morphological variation is the only source of information (i.e., fossil taxa without living representatives) is the implementation of an integrative approach, combining different methodological techniques and a good description of specimens.

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