The Phylogeny of Rays and Skates (Chondrichthyes: Elasmobranchii) Based on Morphological Characters Revisited.

Elasmobranchii are relatively well-studied. However, numerous phylogenetic uncertainties about their relationships remain. Here, we revisit the phylogenetic evidence based on a detailed morphological re-evaluation of all the major extant batomorph clades (skates and rays), including several holomorphic fossil taxa from the Palaeozoic, Mesozoic and Cenozoic, and an extensive outgroup sampling, which includes sharks, chimaeras and several other fossil chondrichthyans.

Revision of the Eocene '' species from the Bolca Lagerstätte (Italy) reveals the first panray (Batomorphii: Zanobatidae) in the fossil record.

The fossil-Lagerstätte of Bolca (Italy) is well known for the diversity and exquisite preservation of its bony and cartilaginous fishes documenting tropical shallow-water marine environments associated with coral reefs in the western Tethys during the early Eocene. In this study, the taxonomic, systematic and phylogenetic position of two batoid species traditionally assigned to the living thornback ray genus is re-evaluated. † Heckel, 1851 is recognized as a separate species of the Platyrhinidae because of its plate-like antorbital cartilage with an irregular outline and a small horn on the nasal capsules.

Integrating the Principles and Practice of Scholarly Activity Into Undergraduate Medical Education: A Narrative Review and Proposed Model for Implementation.

The osteopathic undergraduate medical education standards have evolved over the past 2 decades to require undergraduate medical student participation in research and scholarly activity. The authors' objective was to review those evolving standards and develop a model for introducing the principles and practice of research that combines core content with experiential learning. They identified fundamental topics pertinent to the research process and herein provide their recommendations for incorporating these topics into the curriculum as self-study, online modules, and team-based and active learning exercises.

Evaluating the Influence of Research on Match Success for Osteopathic and Allopathic Applicants to Residency Programs.

Context: Analyzing factors that may enhance osteopathic applicants' likelihood of matching is warranted given that United States osteopathic and allopathic residency programs will have a single accreditation system in 2020.

Objectives: To determine the impact of research accomplishments and experiences on osteopathic and allopathic residency matching.

Methods: Analysis of variance, t test, and odds ratios were used to examine data from the National Resident Matching Program Charting Outcomes from 2016 and 2018.

Revision of Eocene electric rays (Torpediniformes, Batomorphii) from the Bolca Konservat-Lagerstätte, Italy, reveals the first fossil embryo in marine batoids and provides new insights into the origin of trophic novelties in coral reef fishes.

The Eocene electric ray † Carvalho, 2010 from the Bolca Konservat-Lagerstätte, north-eastern Italy, is redescribed in detail based upon new material from recent excavations. This taxon exhibits a combination of features (large voids between the pectoral and the axial skeleton filled in life by electric organs, anteriorly directed fan-shaped antorbital cartilages, lack of dermal denticles, long prepelvic processes, and rounded basibranchial copula with a small caudal tab) that clearly supports its assignment to the order Torpediniformes. The analysis of new material also demonstrates that the previous apparent absence of typical narcinoid characters used to diagnose † was the result of taphonomic biases.

A new genus and species of marine catfishes (Siluriformes; Ariidae) from the upper Eocene Birket Qarun Formation, Wadi El-Hitan, Egypt.

Wadi El-Hitan, the UNESCO World Heritage Site, of the Fayum Depression in the northeast part of the Western Desert of Egypt, has produced a remarkable collection of Eocene vertebrates, in particular the fossil whales from which it derives its name. Here we describe a new genus and species of marine catfishes (Siluriformes; Ariidae), Qarmoutus hitanensis, from the base of the upper Eocene Birket Qarun Formation, based on a partial neurocranium including the complete left side, partial right dentary, left suspensorium, two opercles, left pectoral girdle and spine, nuchal plates, first and second dorsal spines, Weberian apparatus and a disassociated series of abdominal vertebrae. All of the elements belong to the same individual and some of them were found articulated.

The impacts of comparative anatomy of electric rays (Batoidea: Torpediniformes) on their systematic hypotheses.

The Comparative anatomy of the 11 recognized genera within Torpediniformes is described, systematically categorized, and illustrated in a comprehensive photo-atlas. Data are compiled into a character matrix and cladistically analyzed using parsimony to test hypotheses about the previously recognized subfamilies, while reconstructing the possible evolutionary history of Torpediniformes. Results are consistent with the previous rank-based classifications, regardless of the parsimony criteria used to generate the phylogenetic hypothesis, with one notable exception: a monophyletic Narcininae was never recovered.

The synarcual cartilage of batoids with emphasis on the synarcual of Rajidae.

Comparison of embryonic specimens with juvenile and mature specimens of other skates indicates that the relative developmental sequence of events is maintained among several taxa within larger clades. However, there is a fundamental difference between the pattern of chondrification and the pattern of calcification in skates. Early in ontogeny a short synarcual surrounds the first free vertebral centrum.

New interpretations of the skull of a primitive bony fish Erpetoichthys calabaricus (Actinopterygii: Cladistia).

Polypterid fishes are considered the basalmost group of extant actinopterygians and may be a direct link to understanding the systematics and evolution of the first bony fishes. Several investigations have been conducted on one member genus, Polypterus; however, since the first specimens of its sister taxon Erpetoichthys calabaricus were described, remarkably little work has been done on the species. We review terminology critical to understanding cranial morphology in polypterids and present a new description of the skull of E.