Firm attachments binding muscles to skeleton are crucial mechanical components of the vertebrate body. These (entheses) complex three-dimensional structures, containing distinctive arrangements cells and fibre systems embedded in bone, which can be modified during ontogeny. Until recently it has only been possible obtain 2D surface thin section images entheses, leaving their 3D histology largely unstudied except by extrapolation from data. Entheses frequently preserved fossil bones, but...

The transition from jawless to jawed vertebrates (gnathostomes) resulted in the reconfiguration of muscles and skeleton head, including creation a separate shoulder girdle with distinct neck muscles. We describe here only known examples preserved musculature placoderms (extinct armored fishes), phylogenetically most basal vertebrates. Placoderms possess regionalized muscular anatomy that differs radically extant sharks, which is often viewed as primitive for gnathostomes. placoderm data...

The origin and early diversification of jawed vertebrates involved major changes to skeletal soft anatomy. Skeletal transformations can be examined directly by studying fossil stem gnathostomes; however, preservation anatomy is rare. We describe the only known example a three-dimensionally mineralized heart, thick-walled stomach, bilobed liver from arthrodire placoderms, gnathostomes Late Devonian Gogo Formation in Western Australia. application synchrotron neutron microtomography this...

Vertebrate palaeontology, essential for understanding the evolutionary processes of backboned animals, has witnessed substantial increase in research activity and publications over past decade. This bibliometric analysis utilising data from DeepBone database, which includes 9,255 literature entries, with 8,259 overlapping entries Web Science, to capture these changes. Our reveals a continuous growth publication volumes decade, alongside marked expansion interdisciplinary collaborations...

Placoderms are considered as the first jawed vertebrates and constitute a paraphyletic group in stem-gnathostome grade. The acanthothoracid placoderms among phylogenetically most basal morphologically primitive gnathostomes, but their neurocranial anatomy is poorly understood. Here we present near-complete three-dimensional skull of Romundina stellina, small Early Devonian from Canadian Arctic Archipelago, scanned with propagation phase contrast microtomography at 7.46 μm isotropic voxel...

Gavinaspis convergens, a new genus and species of the Phyllolepida (Placodermi: Arthrodira), is described on basis skull remains from Late Lochkovian (Xitun Formation, Early Devonian) Qujing (Yunnan, South China). This form displays mosaic characters basal actinolepidoid arthrodires more derived phyllolepids. A hypothesis proposed concerning origin unpaired centronuchal plate by fusion paired central plates into one single dermal element loss nuchal plate. phylogenetic analysis suggests...

The genus Kujdanowiaspis Stensiö, 1942 has long been considered as the archetype of placoderms; hence, it often used outgroup in phylogenetic analyses involving placoderms, or a representative all placoderms for early vertebrate works. Nevertheless, there no real work on taxonomy this since Denison (1978). Here we propose revision material from Old Red Sandstone Podolia (including neurocrania, skull roofs and thoracic armours), together with description unpublished specimens...

Abstract The placoderm fauna of the late Famennian tetrapod‐bearing locality Strud, Belgium, is studied on basis historical and newly collected material. It includes previously described antiarch Grossilepis rikiki , groenlandaspidid Turrisaspis strudensis sp. nov. actinolepidoideid Phyllolepis undulata . P. thoroughly joins list valid species confidently diagnosed. A morphometrical analysis performed centronuchal anterior ventrolateral plates material demonstrates that there only one in...

The morphology of the arthrodire placoderm Yujiangolepis liujingensis Wang, Pan & 1998, from Lower Devonian Guangxi is redescribed, and compared to that basal arthrodires Antarctaspis White, 1968 Antarctica, Toombalepis Young Goujet, 2003 Wuttagoonaspis Ritchie, 1973 Australia, Yiminaspis Dupret, 2008 south China. A very small plate skull roof at junction nuchal, marginal, postorbital, paranuchal plates considered as vestigial homologue anterior in Petalichthyida Acanthothoraci. attributed...

The placoderm fauna of the upper Famennian tetrapod-bearing locality Strud, Belgium, includes antiarch Grossilepis rikiki, arthrodire groenlandaspidid Turrisaspis strudensis and phyllolepidid Phyllolepis undulata. Based on morphological morphometric evidence, specimens from Strud are predominantly recognised as immature this representing a nursery. depositional environment corresponds to channel in an alluvial plain, presence nursery such could have provided nutrients protection offspring....

ABSTRACT A new genus of ‘actinolepid’ arthrodire placoderm, Erikaspis, is named to contain “Kujdanowiaspis” zychi Stensiö, 1945, from the Lochkovian–Pragian deposits (Lower Devonian) Podolia (Ukraine). This occurs together with Kujdanowiaspis 1942, which its type species was previously assigned. Distinctive ornamentation and pattern dermal plates justify this assignment. phylogenetic analysis places gen. nov., as a close relative contemporaneous Sigaspis lepidophora Goujet, 1973,...

CARLOS MARTÍNEZ-PÉREZa, VINCENT DUPRETb, ESTHER MANZANARESa & HÉCTOR BOTELLAa a Department of Geology , University Valencia C/ Doctor Moliner, 50. CP. 46100, Burjassot Spain b Subdepartment Evolutionary Organismal Biology, Physiology and Developmental Biology Centre Uppsala Norbyvägen 18A 752 36, Sweden

ABSTRACT The skull roof of the species Szelepis yunnanensis (Liu, 1979) from Early Devonian Yunnan is redescribed, as well other material previously published. It appears that only holotype S. can be confidently assigned to this genus. fusion preorbital plates into one plate strongly suggests assignment monophyletic family Actinolepididae Gross, 1940, sensu stricto (comprising Actinolepis Agassiz, 1884, and Bollandaspis Schmidt, 1979). This confirmed by a phylogenetic analysis. Hence,...

ABSTRACT Wuttagoonaspida is a very peculiar group of Arthrodira, hitherto known only in the Early-Middle Devonian deposits Australia. The new genus and species Yiminaspis shenme described here from an incomplete skull roof Pragian Zhaotong (Yunnan, South China). Despite sharing some features with Petalichthyida (e.g. two pairs posterior pitlines), it presents many Wuttagoonaspis long preorbital plates not separated by pineal plate, plate placed further anteriorly orbits). Some thoracic armor...

Material of the antiarch placoderm Bothriolepis from middle Givetian Valentia Slate Formation in Iveragh Peninsula, Ireland, is described and attributed to a new species, B. dairbhrensis sp. nov. A revision genus proposed, its taxonomic content previous phylogenetic analyses are reviewed, as well validity morphologic characteristics considered important for establishment genus, such shape preorbital recess neurocranium. series computerised was performed, which reveals that our species sister...

A new species of the phlyctaeniid arthrodire genus Groenlandaspis from upper Famennian Belgium is described. The remains potyi, sp. nov., consist dissociated thoracic armor elements, but specimen designated to be holotype displays median dorsal, anterior, and posterior dorsolateral plates in articulation. Though incomplete, characterized by an equilateral triangle-shaped dorsal plate, a protruding posterodorsal apron plate behind overlap area for overall lack ornamentation. constitutes...

The siliciclastic sequence of the Lower Devonian southern part Holy Cross Mountains in Poland is renown for abundant vertebrate fossils, including ostracoderm, sarcopterygian, acanthodian, chondrichthyan, and placoderm remains.Study assemblage from "placoderm sandstone" Podłazie Hill reveals that remains belong to Kujdanowiaspis sp.among other unspecified actinolepids brachythoracids.The Polish actinolepid material characterised by sizes bigger than those Podolian specimens; this may be...

ABSTRACT The acanthothoracid Hagiangella goujeti Janvier, 2005, has been described exclusively on the basis of isolated thoracic plates from Lochkovian (Lower Devonian) Khao Loc Formation Tung Vai, Ha Giang Province, northern Vietnam. It is characterized by a very high, triangular median crest dorsal plate, and referred to Acanthothoraci morphology its fused anterolateral, spinal anterior ventrolateral plates, characteristic stellate ornamentation group. Isolated H. are relatively abundant...