The youngest occurrence of embolomeres (Tetrapoda: Anthracosauria) from the Sunjiagou Formation (Lopingian, Permian) of North China

Abstract. Embolomeri were semiaquatic predators prevalent in the Carboniferous, with only two species from the early Permian (Cisuralian). A new embolomere, Seroherpeton yangquanensis gen. et sp. nov. (Zoobank Registration number: urn:lsid:zoobank.org:act:790BEB94-C2CC-4EA4-BE96-2A1BC4AED748, registration: 23 November 2020), is named based on a partial right upper jaw and palate from the Sunjiagou Formation of Yangquan, Shanxi, China, and is late Wuchiapingian (late Permian) in age. It is the youngest embolomere known to date and the only embolomere reported from North China Block. Its phylogenetic position within Embolomeri is confirmed by the strongly developed descending flange on the quadrate ramus of the pterygoid. The new taxon is unique among embolomeres by features like a partial coverage of a denticle shagreens on the pterygoid; presence of a cylindrical shaft on the pterygoid, and two pairs of very large ectopterygoid tusks. Phylogenetic analysis shows Seroherpeton as being the sister group of a clade consisting of Proterogyrinus, Archeria, and Pholiderpeton. We hypothesize that the dispersal and decline of the embolomeres from Carboniferous to late Permian (Lopingian) is related to the climate changes, especially aridification, of the paleotropical regions.

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A phylogeny of Plesiosauria (Sauropterygia) and its bearing on the systematic status of Leptocleidus Andrews, 1922

Zootaxa ◽

10.11646/zootaxa.1863.1.1 ◽

2008 ◽

Vol 1863 (1) ◽

pp. 1 ◽

Cited By ~ 74

Author(s):

PATRICK S. DRUCKENMILLER ◽

ANTHONY P. RUSSELL

Keyword(s):

Late Jurassic ◽

Cladistic Analysis ◽

Sister Group ◽

Phylogenetic Position ◽

Sister Group Relationship ◽

New Taxon ◽

Short Neck ◽

Operational Taxonomic Units ◽

Phylogenetic Hypotheses ◽

The Uk

Leptocleidus Andrews, 1922 is a poorly known plesiosaur genus from Lower Cretaceous successions of the UK, South Africa, and Australia. Historically, there has been little consensus regarding its phylogenetic position within Plesiosauria, largely because of its seemingly aberrant combination of a relatively small skull and short neck. As a result, a diverse array of potential sister groups have been posited for Leptocleidus, including long-necked Cretaceous elasmosaurids, Early Jurassic “rhomaleosaurs”, and Middle to Late Jurassic pliosaurids. A cladistic analysis including Leptocleidus, and a new, apparently morphologically similar specimen from Alberta, TMP 94.122.01, was undertaken to assess their phylogenetic position within Plesiosauria. A character-taxon matrix was assembled afresh, consisting of 33 operational taxonomic units sampled broadly among plesiosaurs. 185 cranial and postcranial characters used in plesiosaur phylogenetics were critically reanalyzed, of which 152 were employed in the parsimony analysis. The results indicate a basal dichotomous split into the traditionally recognized pliosauroid and plesiosauroid clades. Nested within Pliosauroidea, a monophyletic Leptocleididae was recovered, consisting of L. superstes Andrews, 1922 and L. capensis (Andrews, 1911a). In contrast to earlier suggestions, Leptocleidus neither clusters with Rhomaleosaurus, which was found to be paraphyletic, nor with large-skulled pliosaurid taxa, such as Simolestes. Rather, a sister group relationship between Cretaceous Polycotylidae and Leptocleididae was recovered, which is here named Leptocleidoidea. Although TMP 94.122.01 is superficially similar to Leptocleidus, several discrete characters of the skull nest this new taxon within Polycotylidae. Compared to other phylogenetic hypotheses of plesiosaurs, these results are more congruent with respect to the stratigraphic distribution of leptocleidoids. A classification for Plesiosauria is presented.

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Prosogynopora riseri, gen. et sp. nov., a phylogenetically problematic lithophoran proseriate (Platyhelminthes : Rhabditophora) with inverted genital pores from the New England coast

Invertebrate Systematics ◽

10.1071/is13056 ◽

2014 ◽

Vol 28 (3) ◽

pp. 309 ◽

Cited By ~ 3

Author(s):

Christopher E. Laumer ◽

Gonzalo Giribet ◽

Marco Curini-Galletti

Keyword(s):

New England ◽

Sister Group ◽

Optimality Criteria ◽

Phylogenetic Position ◽

28S Rrna ◽

New Taxon ◽

Taxonomic Rank ◽

Molecular Phylogenetic ◽

Pore Opening ◽

Group Relationships

A new lithophoran proseriate flatworm, Prosogynopora riseri, gen. et sp. nov. (Platyhelminthes: Rhabditophora: Proseriata), is described from the New England coast (USA). The species shares characters with members of the families Calviriidae and Coelogynoporidae, e.g. the presence of paracnida, the short common female duct, a septum and diaphragm at the base of the pharynx. However, the inverted topology of the genital system, presenting an anterior female pore shortly behind the mouth and a male pore opening nearly on the caudal terminus, is unique within the Proseriata, and permits inclusion into neither family on morphological grounds. We investigated the phylogenetic position of the new species within the available diversity of proseriate 18S and 28S rRNA sequences. However, an exploration of diverse homology schemes, alignment conditions and optimality criteria proved the position of P. riseri, gen. et sp. nov. to be remarkably unstable, particularly with respect to the method of alignment, variously suggesting sister-group relationships with (or within) Coelogynoporidae, with Calviriidae, or with a clade composed of all other Lithophora. Despite its unique morphology and the absence of molecular phylogenetic evidence for its inclusion within any family as currently defined, we refrain from assigning a higher taxonomic rank to the new lineage, pending critical re-assessment of homology in several character systems and the availability of further taxon- and gene-rich enquiries into the phylogeny of Proseriata. Apingospermata, new taxon and Dolichogynoducta, new taxon are proposed as two rankless taxonomic names of Lithophora, corresponding to well-supported clades in our molecular phylogenetic hypothesis.

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Description and relationships of Otothyropsis marapoama, a new genus and species of hypoptopomatine catfish (Siluriformes: Loricariidae) from rio Tietê basin, southeastern Brazil

Neotropical Ichthyology ◽

10.1590/s1679-62252005000400006 ◽

2005 ◽

Vol 3 (4) ◽

pp. 489-498 ◽

Cited By ~ 19

Author(s):

Alexandre C. Ribeiro ◽

Murilo Carvalho ◽

Alex L. A. Melo

Keyword(s):

New Genus ◽

Sister Group ◽

Headwater Stream ◽

Southeastern Brazil ◽

Phylogenetic Position ◽

New Taxon ◽

New Genus And Species ◽

Paraná Basin ◽

Parana Basin

Otothyropsis marapoama, a new genus and species, is described based on specimens recently collected in a headwater stream of the middle stretch of the rio Tietê, a river from the upper rio Paraná basin in southeastern Brazil. The new taxon belongs to a clade also encompassing the genera Schizolecis, Otothyris and Pseudotothyris. Otothyropsis marapoama is hypothesized to be the sister-group of Pseudotothyris and Otothyris based mainly on the presence of several derived characters of the swimbladder capsule and associated bones. Several paedomorphic characters shared by Pseudotothyris and Otothyris and their significance for the phylogenetic position of the new genus are discussed.

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New material of the ‘microsaur’ Llistrofus from the cave deposits of Richards Spur, Oklahoma and the paleoecology of the Hapsidopareiidae

PeerJ ◽

10.7717/peerj.6327 ◽

2019 ◽

Vol 7 ◽

pp. e6327 ◽

Cited By ~ 6

Author(s):

Bryan M. Gee ◽

Joseph J. Bevitt ◽

Ulf Garbe ◽

Robert R. Reisz

Keyword(s):

Evolutionary History ◽

Substantial Reduction ◽

Sister Group ◽

Phylogenetic Position ◽

Neutron Tomography ◽

Early Permian ◽

Cave Deposits ◽

Internal Structures ◽

History Of ◽

New Material

The Hapsidopareiidae is a group of “microsaurs” characterized by a substantial reduction of several elements in the cheek region that results in a prominent, enlarged temporal emargination. The clade comprises two markedly similar taxa from the early Permian of Oklahoma, Hapsidopareion lepton and Llistrofus pricei, which have been suggested to be synonymous by past workers. Llistrofus was previously known solely from the holotype found near Richards Spur, which consists of a dorsoventrally compressed skull in which the internal structures are difficult to characterize. Here, we present data from two new specimens of Llistrofus. This includes data collected through the use of neutron tomography, which revealed important new details of the palate and the neurocranium. Important questions within “Microsauria” related to the evolutionary transformations that likely occurred as part of the acquisition of the highly modified recumbirostran morphology for a fossorial ecology justify detailed reexamination of less well-studied taxa, such as Llistrofus. Although this study eliminates all but one of the previous features that differentiated Llistrofus and Hapsidopareion, the new data and redescription identify new features that justify the maintained separation of the two hapsidopareiids. Llistrofus possesses some of the adaptations for a fossorial lifestyle that have been identified in recumbirostrans but with a lesser degree of modification (e.g., reduced neurocranial ossification and mandibular modification). Incorporating the new data for Llistrofus into an existing phylogenetic matrix maintains the Hapsidopareiidae’s (Llistrofus + Hapsidopareion) position as the sister group to Recumbirostra. Given its phylogenetic position, we contextualize Llistrofus within the broader “microsaur” framework. Specifically, we propose that Llistrofus may have been fossorial but was probably incapable of active burrowing in the fashion of recumbirostrans, which had more consolidated and reinforced skulls. Llistrofus may represent an earlier stage in the step-wise acquisition of the derived recumbirostran morphology and paleoecology, furthering our understanding of the evolutionary history of “microsaurs.”

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Amphibioplanidae: a new branch and family on the phylogenetic tree of the triclad flatworms (Platyhelminthes: Tricladida), represented by a species from Sardinian caves with a remarkable lifestyle

Zoological Journal of the Linnean Society ◽

10.1093/zoolinnean/zlaa183 ◽

2021 ◽

Author(s):

Giacinta Angela Stocchino ◽

Daniel Dols-Serrate ◽

Ronald Sluys ◽

Marta Riutort ◽

Carlo Onnis ◽

...

Keyword(s):

New Species ◽

Phylogenetic Tree ◽

Sister Group ◽

Phylogenetic Position ◽

Sister Group Relationship ◽

New Taxon ◽

Terrestrial Environment ◽

New Family ◽

Separate Branch ◽

Mediterranean Island

Abstract In this study we document the phylogenetic position and the anatomical and ecological characteristics of a new taxon of cave-dwelling triclad flatworms. This species from the Mediterranean island of Sardinia (Italy) forms a separate branch on the phylogenetic tree of the planarians for which we proposed a new genus and placed it in a new family. Molecular analysis reveals a sister-group relationship between this new family, Amphibioplanidae, and the family Dimarcusidae of the suborder Cavernicola, together constituting the sister-group of the suborder Maricola. The new species Amphibioplana onnisi Stocchino & Sluys, sp. nov. is slender and furnished with an epidermis that is abundantly and uniformly provided with cilia and rhabdites. The pharynx presents an oesophageal projection pointing into the pharynx lumen. Ovaries are located far behind the brain. A relatively long common oviduct opens into the diverticulum of the bursal canal. The probursal copulatory bursa is lined with a highly vacuolated, syncytial epithelium. The habitat of this species is formed by groundwater in microcrevices of the epikarst and temporary cave pools, but the animals can survive in a basically terrestrial environment, thus exhibiting an amphibious lifestyle. Some tentative scenarios are discussed for the evolution of the new taxon and for the presence of the new species in three separate caves in Sardinia.

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