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We describe a new specimen attributed toMacranhinga ranzii, a taxon whose holotype is a left femur, being collected from rocks in the Solimões formation, Southwestern Amazon. The new material is an almost complete pelvic girdle and synsacrum (UFAC 6471), collected in a new fossiliferous locality named Cajueiro. The compatibility between the diameter of foramen acetabuli of UFAC 6471 with the caput femoris of the holotype and the synapomorphies present in the specimen allowed us to attribute it to M. ranzii and emend the diagnosis for this species. Based on three linear measurements of the pelvic girdle and the medium weight of extant Anhinga, we estimate the adult animal's body mass at 8.6 kg. The phylogenetic inference resulted in two equally probable evolutionary hypotheses: one of them with a monophyletic Macranhinga and in the other Meganhinga chilensis as the sister clade of a Macranhinga (in part) plus Anhinga clade. In both scenarios, Macranhinga ranzii is closely related to G. kiyuensis. The morphological and myological data gained in this study enabled us to recognise Macranhinga ranzii as a proficient swimmer and diver, and consequentially a skilled fish hunter in deep waters. [ABSTRACT FROM AUTHOR]

While the holotype of Temnodontosaurus crassimanus still remains on display at the Yorkshire Museum, it has remained largely understudied and the validity of the species has long been questioned. Through re-examination, this study highlights several morphological features of the postcranial skeleton and determines that T. crassimanus is a valid species of the genus and includes several distinct characters that can be used to distinguish it from T. trigonodon, to which it was once assigned. These include a large, robust humerus that is proximodistally longer than the scapula (scapula length vs humerus length ratio: ~0.68); forefins which are significantly longer but less than twice the length of the hindfin (forefin length vs hindfin length ratio: ~1.51); the relative size of the forefins compared with the total body length; along with several other characters that may prove to be unique, such as humerus distal width almost equal to humerus length; presence of notching in at least five leading edge elements of both the fore- and hindfins; and anteroposteriorly wider fore- and hindfins compared with T. trigonodon. Additional specimens, previously tentatively assigned to T. crassimanus, were located and examined, but none could confidently be assigned to the species. [ABSTRACT FROM AUTHOR]

A new ichthyodectiform fish, Amakusaichthys goshouraensis gen. et sp. nov. is described based on several specimens from the Late Cretaceous (Santonian) Hinoshima Formation of the Himenoura Group at Goshoura, Amakusa, Kumamoto in Kyushu, Japan. Amakusaichthys is hypothesized to form a clade with the genus Heckelichthys from the North Atlantic and western Tethyan regions. This new species is highly distinct from other ichthyodectiforms in having the long snout and small mouth with fine conical teeth, which indicates this group had greater diversity than it had been thought. [ABSTRACT FROM AUTHOR]

In 1806, a hypothesis in which hagfishes and lampreys were classified as the taxon Cyclostomi was proposed on the basis of shared morphological traits. That ‘monophyletic cyclostome’ classification prevailed into the twentieth century and has persisted until the present. In 1958, a study involving coordinate grid transformations to analyse head ontogenies for living and fossil craniates was published. Results obtained in that evolutionary–developmental analysis revealed that extant hagfishes and extinct heterostracans developed substantially differently from closely related extant and extinct agnathans and warranted recognition as a distinct lineage. In 1977, a classification in which lampreys and jawed vertebrates formed a group exclusively from hagfishes was proposed on the basis of neontological, morphological and molecular traits. This ‘paraphyletic cyclostome’ classification garnered acceptance among some taxonomists and has persisted alongside the monophyletic cyclostome classification until the present. We applied geometric morphometrics to data obtained from the 1958 evolutionary–developmental analysis, to objectively test and confirm these overlooked and underappreciated results. We demonstrated that the paraphyletic cyclostome classification was conceived at least 19 years earlier than usually acknowledged. Our reanalysis emphasises that the debate on whether the Cyclostomata is monophyletic or paraphyletic must be resolved formally on the basis of principles and practices for phylogenetic systematic analysis including fossil data. [ABSTRACT FROM PUBLISHER]

Elasmobranch fossils recovered from Campanian marine exposures at Elizabethtown, Bladen County, NC, include species from at least seven genera of sharks and four genera of batoids. Of particular interest is the recovery of multiple isolated rostral spines from a new sclerorhynchid sawfish, Borodinopristis shannoni, sp. nov. Species of Borodinopristis are known from oral teeth and/or rostral spines (‘rostral teeth’ for some authors). In species known from the latter, the spines differ from those of other sclerorhynchids by the presence of one or more ‘collared’ barbs on the posterior margin of the crown. Unlike the previously described B. schwimmeri, the rostral spines of the new species have well-developed hooked barbs with collars (curved, connected crests) extending asymmetrically onto the dorsal and ventral surfaces of the spine, as well as small, rudimentary barbs. Also unlike B. schwimmeri, the anterior margin of the spine is strongly convex and there is no enamelled collar at the base of the crown. The new species also occurs in the Upper Cretaceous of the Gulf Coastal Plain. [ABSTRACT FROM PUBLISHER]

Coelacanths have a long fossil record spanning from Early Devonian to the present globally, but until now only from Permian and Triassic sediments in Texas. Reported here is a partial skull, including an articulated lower jaw and disarticulated cranial elements, of a new coelacanth fish (Sarcopterygii: Actinistia) from the Early Cretaceous (Albian) of northern Texas. The presence of a single large pore opening for the supraorbital sensory canal, lack of ornamentation of the cheek and opercular bones, the presence of a few large pore openings in the cheekbones (five or less in the lachrymojugal, one in the other cheekbones) and the presence of small teeth are characters placing this specimen within a new clade along with the genera Libys, Ticinepomis and Diplurus. An upturned symphysis, unornamented gular plates whose posterior margins taper to points, and angular with sinuous dorsal edges reaching the same dorsal extent as the dentary are characters that make this specimen morphologically unique among the new clade. This specimen represents a new species here named as Reidus hilli. [ABSTRACT FROM AUTHOR]

A new tristichopterid, †Bruehnopteron murphyi n. gen. n. sp., is described from the uppermost Givetian, Middle Devonian, from the Northern Simpson Park Range in central Nevada, USA. A complete morphological description is provided. The new tristichopterid is placed between †Jarvikina and †Heddleichthys in recently published phylogenetic diagrams of tristichopterid sarcopterygians. Shape of lacrimal and jugal and the longest preorbital region of all tristichopterids are unique features of the new form. The new tristichopterid has enlarged premaxillary ‘pseudofangs’ and anterior dentary fangs, features of ‘moderately derived’ tristichopterids. [ABSTRACT FROM AUTHOR]

The origin of osteichthyans (bony fishes and tetrapods) dates back to the Late Silurian, but the early evolution of the group is poorly understood. Andreolepis is one of the oldest known osteichthyans, but exclusively documented by detached and fragmentary dermal microremains. A large data-set of Andreolepis scales from the Silurian of Gotland has been used to explore the scale morphology on different parts of the body. Landmark-based geometric morphometrics together with comparative anatomy and functional morphology has allowed 10 morphotypes to be identified and incorporated into a squamation model, in which scales are allocated to anterior-mid lateral flank scales, posterior lateral flank scales, caudal peduncle scales, pectoral peduncle scales, dorsal flank scales, dorsal fulcral scales, caudal fulcral scales, ventral flank scales, medioventral scales and cranial scales. The scale morphology and squamation pattern of Andreolepis may be primitive for the Osteichthyes and thus informative about the acquisition of the osteichthyan body plan. [ABSTRACT FROM AUTHOR]