scholarly journals Cranial anatomy of Bolotridon frerensis, an enigmatic cynodont from the Middle Triassic of South Africa, and its phylogenetic significance

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11542
Author(s):  
Luisa C. Pusch ◽  
Christian F. Kammerer ◽  
Jörg Fröbisch
Keyword(s):  
Middle Triassic ◽  
Phylogenetic Analyses ◽  
Data Matrix ◽  
Phylogenetic Position ◽  
Published Data ◽  
Dental Morphology ◽  
Ct Reconstruction ◽  
Computed Tomographic ◽  
Lower Jaw ◽  
Assemblage Zone

The cynodont fauna of the Trirachodon-Kannemeyeria Subzone of the Middle Triassic Cynognathus Assemblage Zone (AZ) is almost exclusively represented by taxa belonging to the clade Eucynodontia. However, there is one basal (non-eucynodont) cynodont known to have survived into this assemblage: the enigmatic Bolotridon frerensis. BSPG 1934-VIII-7 represents by far the most extensive specimen of B. frerensis, consisting of a partial skull with occluded lower jaw. The specimen was initially described by Broili & Schröder (1934), but their description was limited to surface details of the skull and the dental morphology. Here, by using a computed tomographic (CT) reconstruction, we redescribe this specimen, providing novel information on its palatal and internal anatomy. New endocranial characters recognized for this taxon include ridges in the nasal cavity indicating the presence of cartilaginous respiratory turbinals. New data obtained from the CT scan were incorporated into the most recently published data matrix of early non-mammalian cynodonts to test the previously unstable phylogenetic position of Bolotridon. Our phylogenetic analyses recovered Bolotridon as the sister-taxon of Eucynodontia, a more crownward position than previously hypothesized.

scholarly journals Morphology of the suspensorial, jaw, and opercle musculature of Beloniformes and related species (Teleostei: Acanthopterygii), with a special reference to the m. adductor mandibulae complex

2014 ◽  
Author(s):  
Ingmar Werneburg
Keyword(s):  
Related Species ◽  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Closely Related Species ◽  
Jaw Bones ◽  
Morphological Findings ◽  
Lower Jaw ◽  
Flying Fishes ◽  
Reduced Mobility ◽  
Jaw Musculature

The taxon Beloniformes represents a heterogeneous group of teleost fishes that show an extraordinary diversity of jaw morphology. I present new anatomical descriptions of the jaw musculature in six selected beloniforms and four closely related species. A reduction of the external jaw adductor (A1) and a changed morphology of the intramandibular musculature were found in many Beloniformes. This might be correlated with the progressively reduced mobility of the upper and lower jaw bones. The needlefishes and sauries, which are characterised by extremely elongated and stiffened jaws, show several derived characters, which in combination enable the capture of fish at high velocity. The ricefishes are characterised by several derived and many plesiomorphic characters that make broad scale comparisons difficult. Soft tissue characters are highly diverse among hemiramphids and flying fishes reflecting the uncertainty about their phylogenetic position and interrelationship. The morphological findings presented herein may help to interpret future phylogenetic analyses using cranial musculature in Beloniformes.

scholarly journals Braincase and Inner Ear Anatomy of the Late Carboniferous Tetrapod Limnoscelis dynatis (Diadectomorpha) Revealed by High-Resolution X-ray Microcomputed Tomography

2021 ◽  
Vol 9 ◽  
Author(s):  
Jozef Klembara ◽  
Marcello Ruta ◽  
Miroslav Hain ◽  
David S. Berman
Keyword(s):  
High Resolution ◽  
Semicircular Canals ◽  
Sister Group ◽  
Microcomputed Tomography ◽  
Data Matrix ◽  
Phylogenetic Position ◽  
Published Data ◽  
X Ray ◽  
Character Weighting ◽  
Anterior Semicircular Canal

The braincase anatomy of the Pennsylvanian diadectomorph Limnoscelis dynatis is described in detail, based upon high-resolution X-ray microcomputed tomography. Both supraoccipitals and most of the prootics and opisthotics are preserved. The known portions of the left prootic, opisthotic, and supraoccipital enclose complete sections of the endosseous labyrinth, including the anterior, posterior, and lateral semicircular canals, the vestibule, the cochlear recess, and the canal for the endolymphatic duct. The fossa subarcuata is visible anteromedial to the anterior semicircular canal. The presumed endolymphatic fossae occur in the dorsal wall of the posteromedial portion of the supraoccipital. Both the fossa subarcuata and the fossa endolymphatica lie in the cerebellar portion of the cranial cavity. In order to investigate the phylogenetic position of L. dynatis we used a recently published data matrix, including characters of the braincase, and subjected it to maximum parsimony analyses under a variety of character weighting schemes and to a Bayesian analysis. Limnoscelis dynatis emerges as sister taxon to L. paludis, and both species form the sister group to remaining diadectomorphs. Synapsids and diadectomorphs are resolved as sister clades in ∼90% of all the most parsimonious trees from the unweighted analysis, in the single trees from both the reweighted and the implied weights analyses, as well in the Bayesian tree.

scholarly journals Morphology of the jaw, suspensorial, and opercle musculature of Beloniformes and related species (Teleostei: Acanthopterygii), with a special reference to the m. adductor mandibulae complex

2015 ◽  
Author(s):  
Ingmar Werneburg
Keyword(s):  
Related Species ◽  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Closely Related Species ◽  
Jaw Bones ◽  
Morphological Findings ◽  
Lower Jaw ◽  
Flying Fishes ◽  
Reduced Mobility ◽  
Jaw Musculature

The taxon Beloniformes represents a heterogeneous group of teleost fishes that show an extraordinary diversity of jaw morphology. I present new anatomical descriptions of the jaw musculature in six selected beloniforms and four closely related species. A reduction of the external jaw adductor (A1) and a changed morphology of the intramandibular musculature were found in many Beloniformes. This might be correlated with the progressively reduced mobility of the upper and lower jaw bones. The needlefishes and sauries, which are characterised by extremely elongated and stiffened jaws, show several derived characters, which in combination enable the capture of fish at high velocity. The ricefishes are characterised by several derived and many plesiomorphic characters that make broad scale comparisons difficult. Soft tissue characters are highly diverse among hemiramphids and flying fishes reflecting the uncertainty about their phylogenetic position and interrelationship. The morphological findings presented herein may help to interpret future phylogenetic analyses using cranial musculature in Beloniformes.

scholarly journals Morphology of the jaw, suspensorial, and opercle musculature of Beloniformes and related species (Teleostei: Acanthopterygii), with a special reference to the m. adductor mandibulae complex

2015 ◽  
Author(s):  
Ingmar Werneburg
Keyword(s):  
Related Species ◽  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Closely Related Species ◽  
Jaw Bones ◽  
Morphological Findings ◽  
Lower Jaw ◽  
Flying Fishes ◽  
Reduced Mobility ◽  
Jaw Musculature

The taxon Beloniformes represents a heterogeneous group of teleost fishes that show an extraordinary diversity of jaw morphology. I present new anatomical descriptions of the jaw musculature in six selected beloniforms and four closely related species. A reduction of the external jaw adductor (A1) and a changed morphology of the intramandibular musculature were found in many Beloniformes. This might be correlated with the progressively reduced mobility of the upper and lower jaw bones. The needlefishes and sauries, which are characterised by extremely elongated and stiffened jaws, show several derived characters, which in combination enable the capture of fish at high velocity. The ricefishes are characterised by several derived and many plesiomorphic characters that make broad scale comparisons difficult. Soft tissue characters are highly diverse among hemiramphids and flying fishes reflecting the uncertainty about their phylogenetic position and interrelationship. The morphological findings presented herein may help to interpret future phylogenetic analyses using cranial musculature in Beloniformes.

scholarly journals An enigmatic lower jaw from the Lower Muschelkalk (Anisian, Middle Triassic) of Winterswijk provides insights into dental configuration, tooth replacement and histology

2021 ◽  
Vol 100 ◽  
Author(s):  
Stephan N.F. Spiekman ◽  
Nicole Klein
Keyword(s):  
Middle Triassic ◽  
Posterior Part ◽  
Dorsal Surface ◽  
Dental Morphology ◽  
Posterior Teeth ◽  
Dental Lamina ◽  
Computed Tomographic ◽  
Anterior Teeth ◽  
Replacement Pattern ◽  
Lower Muschelkalk

Abstract In the aftermath of the Permo-Triassic mass extinction event, several reptile lineages radiated to form major components of marine faunas during the entire Mesozoic. The Lower Muschelkalk, which was deposited within a shallow inland sea in the Germanic Basin during the Middle Triassic, is one of the most important regions for understanding the early evolution of Mesozoic marine reptiles. Here, we present a new specimen from the Lower Muschelkalk of Winterswijk in the Netherlands, comprising an isolated left dentary that is morphologically distinct from any well-known Triassic vertebrate. We provide a detailed description of the jaw and the teeth using histological and micro-computed tomographic analyses. The anterior teeth are fang-like and curved, whereas the posterior teeth are wider and triangular-shaped. Tooth implantation is thecodont and teeth are ankylosed to the base of the alveolus. Replacement teeth are developed directly lingual to the functional teeth, starting with the formation of a resorption cavity on the dorsal surface of the alveolar margin. The replacement pattern cannot be observed in detail but is regular in the posterior part of the dentary with each tooth being alternated with an empty alveolus. The specimen can likely be assigned to Eosauropterygia based on its jaw morphology and dental morphology and replacement pattern, and it is remarkably similar to maxillae referred to the enigmatic Lamprosauroides goepperti from the Lower Muschelkalk of Poland. The dentary from Winterswijk lacks enlarged, ‘alveolarised’ crypts and corresponding distinct dental lamina foramina (DLFs) for the replacement teeth, a configuration that is typical of Sauropterygia, but which was likely not omnipresent in this clade. The specimen also exhibits loosely folded plicidentine at the roots of the teeth, likely representing the first identification of this feature in Sauropterygia.

Telaprocera (Araneae: Araneidae), a new genus of Australian orb-web spiders with highly elongated webs

Zootaxa ◽  
2008 ◽  
Vol 1956 (1) ◽  
pp. 59-80 ◽  
Author(s):  
AARON M. T. HARMER ◽  
VOLKER W. FRAMENAU
Keyword(s):  
New Genus ◽  
Phylogenetic Analyses ◽  
Data Matrix ◽  
Morphological Data ◽  
Phylogenetic Position ◽  
South Wales ◽  
Closed Canopy ◽  
Orb Web ◽  
Orb Web Spiders ◽  
Far Eastern

A new genus of orb-web spider (Araneidae Simon), Telaprocera gen. nov., including two new species, T. maudae sp. nov. (type species) and T. joanae sp. nov., are described. Telaprocera gen. nov. differs from all other araneid genera by the presence of a dorsal keel on the male cymbium. The known range of Telaprocera maudae sp. nov. is limited to the east coast of Australia, from far northern Queensland to central New South Wales. The spiders are found in closed canopy rainforest and adults can be found year round. Telaprocera joanae sp. nov. has been found from central coastal Queensland to far eastern Victoria. They occur in similar habitats, with similar phenology, as T. maudae sp. nov. Both species build highly elongated orb-webs known as ladder-webs. A variety of phylogenetic analyses based on an updated morphological data matrix for orb-web spiders did not provide a conclusive placement of Telaprocera gen. nov. within the Araneidae. Equally weighted analysis placed the genus as sister to Kaira O. P.-Cambridge and Metepeira F. O. P.Cambridge combined. Strong downweighting of homoplasious characters placed the genus as sister taxon to the traditional Argiopinae Simon. The uncertain phylogenetic position of Telaprocera gen. nov. may reflect the insufficient knowledge of the morphology of Australian taxa—taxa that may possess characters previously not considered in phylogenetic analyses of the Araneidae.

scholarly journals Revised Description of the Early Permian Recumbirostran “Microsaur” Nannaroter mckinziei Based on New Fossil Material and Computed Tomographic Data

2021 ◽  
Vol 9 ◽  
Author(s):  
Mark J. MacDougall ◽  
Robert Seeger ◽  
Bryan Gee ◽  
Jasper Ponstein ◽  
Maren Jansen ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Early Permian ◽  
Computed Tomographic ◽  
Lower Jaw ◽  
Fossil Material ◽  
New Information ◽  
Ct Analysis ◽  
Tomographic Data ◽  
Ct Data ◽  
Phylogenetic Character

The early Permian Richards Spur locality of Oklahoma has produced abundant material of numerous terrestrial fossil tetrapods, including various “microsaurs,” several of which are considered to belong to the clade Recumbirostra. We present a new partial skull of the recumbirostran “microsaur” Nannaroter mckinziei; through computed tomography (CT) analysis of both this new specimen and the holotype, we provide an updated description of the taxon. This new description provides novel information regarding several regions that could not be examined previously due to either being absent in the holotype or difficult to access. This includes missing and obscured aspects of the skull roof, braincase, lower jaw, and the palatal region. Furthermore, the new information obtained from this description was used to update phylogenetic character codings of Nannaroter, and a revised phylogenetic analysis was conducted. The results of this updated analysis are congruent with those of other recent phylogenetic analyses of recumbirostran “microsaurs.” This new information adds to the ever-growing body of early tetrapod CT data, which has been, and will continue to be, important in revealing details regarding early tetrapod anatomy, interrelationships, paleoecology, and evolution.

scholarly journals New insights into the morphology of the Carboniferous tetrapodCrassigyrinus scoticusfrom computed tomography

2018 ◽  
Vol 109 (1-2) ◽  
pp. 157-175 ◽  
Author(s):  
Eva C. HERBST ◽  
John R. HUTCHINSON
Keyword(s):  
Phylogenetic Analyses ◽  
Phylogenetic Position ◽  
Neural Arch ◽  
Skeletal Morphology ◽  
Terrestrial Locomotion ◽  
Computed Tomographic ◽  
Selective Pressures ◽  
Functional Implications ◽  
The Matrix ◽  
Important Time

ABSTRACTThe Carboniferous tetrapodCrassigyrinus scoticusis an enigmatic animal in terms of its morphology and its phylogenetic position.Crassigyrinushad extremely reduced forelimbs, and was aquatic, perhaps secondarily. Recent phylogenetic analyses tentatively placeCrassigyrinusclose to the whatcheeriids. Many Carboniferous tetrapods exhibit several characteristics associated with terrestrial locomotion, and much research has focused on how this novel locomotor mode evolved. However, to estimate the selective pressures and constraints during this important time in vertebrate evolution, it is also important to study early tetrapods likeCrassigyrinusthat either remained aquatic or secondarily became aquatic. We used computed tomographic scanning to search for more data about the skeletal morphology ofCrassigyrinusand discovered several elements previously hidden by the matrix. These elements include more ribs, another neural arch, potential evidence of an ossified pubis and maybe of pleurocentra. We also discovered several additional metatarsals with interesting asymmetrical morphology that may have functional implications. Finally, we reclassify what was previously thought to be a left sacral rib as a left fibula and show previously unknown aspects of the morphology of the radius. These discoveries are examined in functional and phylogenetic contexts.

scholarly journals The Complete DNA Sequence of the Mitochondrial Genome of a “Living Fossil,” the Coelacanth (Latimeria chalumnae)

Genetics ◽  
1997 ◽  
Vol 146 (3) ◽  
pp. 995-1010 ◽  
Author(s):  
Rafael Zardoya ◽  
Axel Meyer
Keyword(s):  
Mitochondrial Genome ◽  
Tandem Repeats ◽  
Phylogenetic Analyses ◽  
Large Data ◽  
Molecular Data ◽  
Phylogenetic Position ◽  
Data Set ◽  
Living Fossil ◽  
Latimeria Chalumnae ◽  
Relationship Of

The complete nucleotide sequence of the 16,407-bp mitochondrial genome of the coelacanth (Latimeria chalumnae) was determined. The coelacanth mitochondrial genome order is identical to the consensus vertebrate gene order which is also found in all ray-finned fishes, the lungfish, and most tetrapods. Base composition and codon usage also conform to typical vertebrate patterns. The entire mitochondrial genome was PCR-amplified with 24 sets of primers that are expected to amplify homologous regions in other related vertebrate species. Analyses of the control region of the coelacanth mitochondrial genome revealed the existence of four 22-bp tandem repeats close to its 3′ end. The phylogenetic analyses of a large data set combining genes coding for rRNAs, tRNA, and proteins (16,140 characters) confirmed the phylogenetic position of the coelacanth as a lobe-finned fish; it is more closely related to tetrapods than to ray-finned fishes. However, different phylogenetic methods applied to this largest available molecular data set were unable to resolve unambiguously the relationship of the coelacanth to the two other groups of extant lobe-finned fishes, the lungfishes and the tetrapods. Maximum parsimony favored a lungfish/coelacanth or a lungfish/tetrapod sistergroup relationship depending on which transversion:transition weighting is assumed. Neighbor-joining and maximum likelihood supported a lungfish/tetrapod sistergroup relationship.

scholarly journals Resolving Phylogenetic Relationships within Passeriformes Based on Mitochondrial Genes and Inferring the Evolution of Their Mitogenomes in Terms of Duplications

2019 ◽  
Vol 11 (10) ◽  
pp. 2824-2849 ◽  
Author(s):  
Paweł Mackiewicz ◽  
Adam Dawid Urantówka ◽  
Aleksandra Kroczak ◽  
Dorota Mackiewicz
Keyword(s):  
Phylogenetic Analyses ◽  
Mitochondrial Genes ◽  
The Other ◽  
Phylogenetic Position ◽  
Evolutionary Relationships ◽  
Mitochondrial Genomes ◽  
Ancestral State ◽  
Phylogenetic Information ◽  
Long Time ◽  
Tree Topologies

Abstract Mitochondrial genes are placed on one molecule, which implies that they should carry consistent phylogenetic information. Following this advantage, we present a well-supported phylogeny based on mitochondrial genomes from almost 300 representatives of Passeriformes, the most numerous and differentiated Aves order. The analyses resolved the phylogenetic position of paraphyletic Basal and Transitional Oscines. Passerida occurred divided into two groups, one containing Paroidea and Sylvioidea, whereas the other, Passeroidea and Muscicapoidea. Analyses of mitogenomes showed four types of rearrangements including a duplicated control region (CR) with adjacent genes. Mapping the presence and absence of duplications onto the phylogenetic tree revealed that the duplication was the ancestral state for passerines and was maintained in early diverged lineages. Next, the duplication could be lost and occurred independently at least four times according to the most parsimonious scenario. In some lineages, two CR copies have been inherited from an ancient duplication and highly diverged, whereas in others, the second copy became similar to the first one due to concerted evolution. The second CR copies accumulated over twice as many substitutions as the first ones. However, the second CRs were not completely eliminated and were retained for a long time, which suggests that both regions can fulfill an important role in mitogenomes. Phylogenetic analyses based on CR sequences subjected to the complex evolution can produce tree topologies inconsistent with real evolutionary relationships between species. Passerines with two CRs showed a higher metabolic rate in relation to their body mass.

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