scholarly journals A bird-like skull in a Triassic diapsid reptile increases heterogeneity of the morphological and phylogenetic radiation of Diapsida

2017 ◽  
Vol 4 (10) ◽  
pp. 170499 ◽  
Author(s):  
Adam C. Pritchard ◽  
Sterling J. Nesbitt
Keyword(s):  
Three Dimensional ◽  
Total Body Length ◽  
Phylogenetic Position ◽  
Micro Computed Tomography ◽  
Crown Group ◽  
Chinle Formation ◽  
Total Body ◽  
Permian Mass Extinction ◽  
First Time ◽  
A New Species

The Triassic Period saw the first appearance of numerous amniote lineages (e.g. Lepidosauria, Archosauria, Mammalia) that defined Mesozoic ecosystems following the end Permian Mass Extinction, as well as the first major morphological diversification of crown-group reptiles. Unfortunately, much of our understanding of this event comes from the record of large-bodied reptiles (total body length > 1 m). Here we present a new species of drepanosaurid (small-bodied, chameleon-like diapsids) from the Upper Triassic Chinle Formation of New Mexico. Using reconstructions of micro-computed tomography data, we reveal the three-dimensional skull osteology of this clade for the first time. The skull presents many archaic anatomical traits unknown in Triassic crown-group reptiles (e.g. absence of bony support for the external ear), whereas other traits (e.g. toothless rostrum, anteriorly directed orbits, inflated endocranium) resemble derived avian theropods. A phylogenetic analysis of Permo-Triassic diapsids supports the hypothesis that drepanosaurs are an archaic lineage that originated in the Permian, far removed from crown-group Reptilia. The phylogenetic position of drepanosaurids indicates the presence of archaic Permian clades among Triassic small reptile assemblages and that morphological convergence produced a remarkably bird-like skull nearly 100 Myr before one is known to have emerged in Theropoda.

scholarly journals Differentiated appendages in Isoxys illuminate origin of arthropodization

2021 ◽  
Author(s):  
Caixia Zhang ◽  
Yu Liu ◽  
Javier Ortega-Hernández ◽  
Joanna Wolfe ◽  
Changfei Jin ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Phylogenetic Position ◽  
Burgess Shale ◽  
Micro Computed Tomography ◽  
Major Transition ◽  
New Material ◽  
Feeding Function ◽  
Chengjiang Biota ◽  
First Time

Abstract The Cambrian fossil record has produced remarkable insights into the origin of euarthropods, particularly the evolution of their versatile body plan of segments bearing specialized, jointed appendages for different functions including feeding and locomotion [01, 02]. Early euarthropod evolution involved a major transition from lobopodian-like taxa [03, 04, 05] to organisms featuring a fully sclerotized trunk (arthrodization) and limbs (arthropodization) [02, 06, 07, 08]. However, the precise origin of arthropodization remains controversial because some of the earliest branching euarthropods possess a broad dorsal carapace that obscures critical details of the trunk and appendage organization [09, 10, 11, 12, 13, 14, 15]. Here, we demonstrate the presence of fully arthropodized ventral appendages in the upper stem-group euarthropod Isoxys curvirostratus from the early Cambrian Chengjiang biota in South China. Micro-computed tomography reveals the detailed three-dimensional structure of the biramous appendages in I. curvirostratus for the first time. In addition to the raptorial frontal appendages I. curvirostratus also possesses two batches of morphologically distinct biramous limbs, with the first batch consisting of four pairs of short cephalic appendages bearing prominent endites with a feeding function, followed by a second batch of elongate trunk appendages for locomotion. Each biramous limb bears an endopod with more than 12 well-defined podomeres, and an exopod consisting of a slender shaft carrying approximately a dozen paddle-shaped lamellae. Our findings clarify the enigmatic appendicular organization of Isoxys, one of the most ubiquitous euarthropods in Cambrian Burgess Shale-type deposits worldwide [01, 10, 11, 12, 14, 15, 16, 17, 18]. Critically, our new material shows that the trunk of I. curvirostratus was not arthrodized. The phylogenetic position of isoxyiids as possibly the earliest branching members of Deuteropoda [01, 02, 07, 15, 19], suggests that arthropodized biramous appendages evolved before the pattern of full trunk arthrodization that characterizes most extant and extinct members of this successful animal phylum.

scholarly journals A fresh look at Cladarosymblema narrienense, a tetrapodomorph fish (Sarcopterygii: Megalichthyidae) from the Carboniferous of Australia, illuminated via X-ray tomography

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12597
Author(s):  
Alice M. Clement ◽  
Richard Cloutier ◽  
Jing Lu ◽  
Egon Perilli ◽  
Anton Maksimenko ◽  
...  
Keyword(s):  
Original Description ◽  
Sister Group ◽  
Axial Skeleton ◽  
Phylogenetic Position ◽  
Micro Computed Tomography ◽  
Holotype Specimen ◽  
Freshwater Swamp ◽  
The Family ◽  
First Time ◽  
Detailed Work

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.

scholarly journals Genetic diversity of the genus Terfezia (Pezizaceae, Pezizales): New species and new record from North Africa

Phytotaxa ◽  
2018 ◽  
Vol 334 (2) ◽  
pp. 183 ◽  
Author(s):  
Fatima El-Houaria ZITOUNI-HAOUAR ◽  
JUAN RAMÓN CARLAVILLA ◽  
GABRIEL MORENO ◽  
JOSÉ LUIS MANJÓN ◽  
ZOHRA FORTAS
Keyword(s):  
New Species ◽  
North Africa ◽  
Phylogenetic Analyses ◽  
Ribosomal Subunit ◽  
Morphological Characters ◽  
Phylogenetic Position ◽  
Unique Combination ◽  
Large Ribosomal Subunit ◽  
First Time ◽  
A New Species

Morphological and phylogenetic analyses of large ribosomal subunit (28S rDNA) and internal transcribed spacer (ITS rDNA) of Terfezia samples collected from several bioclimatic zones in Algeria and Spain revealed the presence of six distinct Terfezia species: T. arenaria, T. boudieri, T. claveryi; T. eliocrocae (reported here for the first time from North Africa), T. olbiensis, and a new species, T. crassiverrucosa sp. nov., proposed and described here, characterized by its phylogenetic position and unique combination of morphological characters. A discussion on the unresolved problems in the taxonomy of the spiny-spored Terfezia species is conducted after the present results.

scholarly journals Evolution and palaeoecology of early turtles: a review based on recent discoveries in the Middle Jurassic

2011 ◽  
Vol 182 (3) ◽  
pp. 231-240 ◽  
Author(s):  
Jérémy Anquetin
Keyword(s):  
New Species ◽  
Middle Jurassic ◽  
Morphological Characters ◽  
Early Evolution ◽  
Bone Histology ◽  
Phylogenetic Position ◽  
Crown Group ◽  
Three New Species ◽  
First Time ◽  
Lines Of Evidence

AbstractIn recent years, no less than five new species of early turtles have been described worldwide. Among them are three new turtles from Middle Jurassic deposits that partially fill a previous temporal and morphological gap in our knowledge of the early evolution of these shelled amniotes: Heckerochelys romani, Condorchelys antiqua and Eileanchelys waldmani. For the first time, the phylogenetic position of these three new species is tested in the context of the two presently competing cladistic models of turtle evolution. The addition of these taxa to each matrix does not favour or alter any of the two opposed hypotheses. However, it is demonstrated here that, by documenting yet unknown stages in the evolution of several morphological structures, these three species give stronger support to the model of an extended phylogenetic stem for turtles. These new lines of evidence include the structure of the vomer, the position of the aditus canalis stapedio-temporalis and of the posterior opening of the canalis cavernosus, and the morphology of the processus interfenestralis of the opisthotic.Recent discoveries also reinvigorate the debate about the palaeoecology of early turtles. Whereas simple morphological characters (e.g., shell fontanelle, ligamentous bridge, flattened carapace) can be misleading, forelimb proportions and shell bone histology have led to the conclusion that most stem turtles (i.e., Proganochelys quenstedti, Palaeochersis talampayensis, Proterochersis robusta, Kayentachelys aprix and meiolaniids) were terrestrial forms. At least two out of the five recently described early turtles have been convincingly interpreted as having aquatic habits: Odontochelys semitestacea and Eileanchelys waldmani. More investigation is needed, but this will undoubtedly trigger further debate on the primitive ecology of turtles and on the origin of aquatic habits in testudines (i.e., the crown-group), respectively.

Two species of the genus Kalicephalus Molin, 1861 (Nematoda, Diaphanocephaloidea) from the water monitor, Varanus salvator (Laurenti, 1768) in Guangdong Province, China

2011 ◽  
Vol 56 (1) ◽  
Author(s):  
Haoji Zhang ◽  
Shuqian Zhang ◽  
Luping Zhang
Keyword(s):  
Body Length ◽  
Relative Length ◽  
Guangdong Province ◽  
Host Record ◽  
Total Body Length ◽  
New Host ◽  
New Host Record ◽  
Varanus Salvator ◽  
Total Body ◽  
First Time

AbstractTwo species of Kalicephalus Molin, 1861 were collected from the intestine of Varanus salvator (Laurenti, 1768) from Guangdong Wildlife Rescue Centre, Guangzhou, Guangdong Province, China. Kalicephalus (Kalicephalus) guangdongensis sp. nov. is similar to K. (K.) schadi Ogden, 1966 and K. (K.) schadi fotedari Kalia et Nayital, 1989 in having extremely long spicules, but differs from the latter in the relative length of spicules (spicules longer than the total body length instead of spicules almost three quarters of the total body length). Kalicephalus (Kalicephalus) schadi fotedari Kalia et Nayital, 1989 is reported for the first time in China, and Varanus salvator is a new host record.

scholarly journals Revision of the Late Jurassic teleosaurid genus Machimosaurus (Crocodylomorpha, Thalattosuchia)

2014 ◽  
Vol 1 (2) ◽  
pp. 140222 ◽  
Author(s):  
Mark T. Young ◽  
Stéphane Hua ◽  
Lorna Steel ◽  
Davide Foffa ◽  
Stephen L. Brusatte ◽  
...  
Keyword(s):  
Late Jurassic ◽  
Total Body Length ◽  
Coastal Marine ◽  
Geological Age ◽  
Northeastern France ◽  
Total Body ◽  
Upper Kimmeridgian ◽  
A New Species ◽  
Lines Of Evidence ◽  
Lower Kimmeridgian

Machimosaurus was a large-bodied genus of teleosaurid crocodylomorph, considered to have been durophagous/chelonivorous, and which frequented coastal marine/estuarine ecosystems during the Late Jurassic. Here, we revise the genus based on previously described specimens and revise the species within this genus. We conclude that there were three European Machimosaurus species and another taxon in Ethiopia. This conclusion is based on numerous lines of evidence: craniomandibular, dental and postcranial morphologies; differences in estimated total body length; geological age; geographical distribution; and hypothetical lifestyle. We re-diagnose the type species Machimosaurus hugii and limit referred specimens to only those from Upper Kimmeridgian–Lower Tithonian of Switzerland, Portugal and Spain. We also re-diagnose Machimosaurus mosae , demonstrate that it is an available name and restrict the species to the uppermost Kimmeridgian–lowermost Tithonian of northeastern France. We re-diagnose and validate the species Machimosaurus nowackianus from Harrar, Ethiopia. Finally, we establish a new species, Machimosaurus buffetauti , for the Lower Kimmeridgian specimens of France and Germany (and possibly England and Poland). We hypothesize that Machimosaurus may have been analogous to the Pliocene–Holocene genus Crocodylus in having one large-bodied taxon suited to traversing marine barriers and additional, geographically limited taxa across its range.

scholarly journals Echinoids from the Tesero Member (Werfen Formation) of the Dolomites (Italy): implications for extinction and survival of echinoids in the aftermath of the end-Permian mass extinction

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7361
Author(s):  
Jeffrey R. Thompson ◽  
Renato Posenato ◽  
David J. Bottjer ◽  
Elizabeth Petsios
Keyword(s):  
Mass Extinction ◽  
Sea Urchins ◽  
Northern Italy ◽  
Early Triassic ◽  
Crown Group ◽  
Stem Group ◽  
Extinction Event ◽  
Permian Extinction ◽  
Permian Mass Extinction ◽  
A New Species

The end-Permian mass extinction (∼252 Ma) was responsible for high rates of extinction and evolutionary bottlenecks in a number of animal groups. Echinoids, or sea urchins, were no exception, and the Permian to Triassic represents one of the most significant intervals of time in their macroevolutionary history. The extinction event was responsible for significant turnover, with the Permian–Triassic representing the transition from stem group echinoid-dominated faunas in the Palaeozoic to Mesozoic faunas dominated by crown group echinoids. This turnover is well-known, however, the environmental and taxonomic distribution of echinoids during the latest Permian and Early Triassic is not. Here we report on an echinoid fauna from the Tesero Member, Werfen Formation (latest Permian to Early Triassic) of the Dolomites (northern Italy). The fauna is largely known from disarticulated ossicles, but consists of both stem group taxa, and a new species of crown group echinoid,Eotiaris teseroensisn. sp. That these stem group echinoids were present in the Tesero Member indicates that stem group echinoids did not go extinct in the Dolomites coincident with the onset of extinction, further supporting other recent work indicating that stem group echinoids survived the end-Permian extinction. Furthermore, the presence ofEotiarisacross a number of differing palaeoenvironments in the Early Triassic may have had implications for the survival of cidaroid echinoids during the extinction event.

Hydrolagus erithacus sp. nov. (Chimaeriformes: Chimaeridae), a new species of chimaerid from the southeastern Atlantic and southwestern Indian oceans 

Zootaxa ◽  
2017 ◽  
Vol 4226 (4) ◽  
pp. 509 ◽  
Author(s):  
KRISTIN A. WALOVICH ◽  
DAVID A. EBERT ◽  
JENNY M. KEMPER
Keyword(s):  
New Species ◽  
Body Height ◽  
Total Body Length ◽  
Distinct Species ◽  
Dorsal Fin ◽  
Total Body ◽  
Apex Height ◽  
A New Species ◽  
Southeastern Atlantic ◽  
Pelvic Fin

A new species of chimaerid, Hydrolagus erithacus sp. nov., is described from nine specimens collected from the southeast Atlantic and southwest Indian oceans from depths of 470–1,000 meters. This species is distinguished from all other Hydrolagus species based on the following characteristics: head bulky, relatively large, followed by stocky body; head and body height from about pectoral fin origin to pelvic fin origin similar, then tapering rapidly to filamentous tail; first dorsal fin spine height about equal to, or slightly less than first dorsal fin apex height; second dorsal fin up to 81% of total body length and uniform in height; trifurcate claspers forked for approximately 20% of total length; robust frontal tenaculum nearly uniform in width, prepelvic tenaculae with five to seven medial spines, and a uniform black coloration with robust, non-deciduous skin. Comparison of mitochondrial NADH2 gene sequences with other morphologically similar Hydrolagus species suggests that H. erithacus is a distinct species. 

scholarly journals Enhanced macroboring and depressed calcification drive net dissolution at high-CO 2 coral reefs

2016 ◽  
Vol 283 (1842) ◽  
pp. 20161742 ◽  
Author(s):  
Ian C. Enochs ◽  
Derek P. Manzello ◽  
Graham Kolodziej ◽  
Sam H. C. Noonan ◽  
Lauren Valentino ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Skeletal Structure ◽  
Global Ocean ◽  
Biological Processes ◽  
Micro Computed Tomography ◽  
Dead Coral ◽  
Intergovernmental Panel ◽  
Three Dimensional Models ◽  
First Time ◽  
High Carbon Dioxide

Ocean acidification (OA) impacts the physiology of diverse marine taxa; among them corals that create complex reef framework structures. Biological processes operating on coral reef frameworks remain largely unknown from naturally high-carbon-dioxide (CO 2 ) ecosystems. For the first time, we independently quantified the response of multiple functional groups instrumental in the construction and erosion of these frameworks (accretion, macroboring, microboring, and grazing) along natural OA gradients. We deployed blocks of dead coral skeleton for roughly 2 years at two reefs in Papua New Guinea, each experiencing volcanically enriched CO 2 , and employed high-resolution micro-computed tomography (micro-CT) to create three-dimensional models of changing skeletal structure. OA conditions were correlated with decreased calcification and increased macroboring, primarily by annelids, representing a group of bioeroders not previously known to respond to OA. Incubation of these blocks, using the alkalinity anomaly methodology, revealed a switch from net calcification to net dissolution at a pH of roughly 7.8, within Intergovernmental Panel on Climate Change's (IPCC) predictions for global ocean waters by the end of the century. Together these data represent the first comprehensive experimental study of bioerosion and calcification from a naturally high-CO 2 reef ecosystem, where the processes of accelerated erosion and depressed calcification have combined to alter the permanence of this essential framework habitat.

scholarly journals A new cryptic species of the Pristimantis lacrimosus group (Anura, Strabomantidae) from the eastern slopes of the Ecuadorian Andes

2021 ◽  
Vol 5 ◽  
pp. 151-175
Author(s):  
Julio C. Carrión-Olmedo ◽  
Santiago R. Ron
Keyword(s):  
New Species ◽  
National Parks ◽  
Genetic Distances ◽  
Red List ◽  
Phylogenetic Position ◽  
Advertisement Call ◽  
Anthropogenic Influences ◽  
Undescribed Species ◽  
First Time ◽  
A New Species

With 566 species, the neotropical genus Pristimantis is the most speciose vertebrate genus. As a result of its striking diversity, taxonomic reviews remain a challenge. Herein, we present an updated phylogeny of the Pristimantis lacrimosus group and describe a new species from Llanganates and Sangay National Parks. We also report, for the first time, the phylogenetic position of Pristimantis degener, P. eugeniae, P. katoptroides, and P. petersi. Based on our phylogeny, we add two species to the Pristimantis lacrimosus group. Through the integration of molecular and bioacoustic evidence, we describe a new species which was hidden under “Pristimantis petersi”. Pristimantis petersioidessp. nov. is most closely related to Pristimantis petersi and an undescribed species from Peru. It can be distinguished from P. petersi by its advertisement call and large genetic differences (uncorrected p-genetic distances 7.9% to 8.4% for gene 16S). Moreover, the new species and P. petersi are not sister species. We suggest assigning the new species to the Endangered Red List category because it has a small distribution range with deforestation as result of agriculture and other anthropogenic influences.

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