New Triassic teleosts (Actinopterygii, Teleosteomorpha) from northern Italy and their phylogenetic relationships among the most basal teleosts

<p>This study provides new evidence of the diversity of Middle–Late Triassic teleosts with the description of new pholidophorids from Italy. The results of the phylogenetic analysis confirm the sister-group relationship [†Aspidorhynchiformes + †Pachycormiformes] as members of Teleosteomorpha and †<i>Prohalecites</i> as the oldest teleosteomorph. The apomorphy-based Teleostei includes a new interpretation of †Pholidophoriformes as a monophyletic group supported by numerous synapomorphies and comprising two families, †Pholidophoridae and †Eurycormidae, fam. nov. The latter is only known from the Upper Jurassic of Europe. The monophyletic family †Pholidophoridae is known by about a dozen European taxa and a Middle Triassic genus (†<i>Malingichthys</i>) from southern Asia, which is the oldest member of the family. The addition of new pholidophorids provides a new interpretation of the possible relationships and taxonomic arrangements within the family †Pholidophoridae. The genera †<i>Pholidorhynchodon</i> and †<i>Eopholidophorus</i> stand as pholidophorids with a unique morphology of the upper oral margin, including a median rostral bone bearing a few large conical teeth, laterodermethmoids armed with large teeth, and the premaxillae displaced from the middle region of the oral margin. This study confirms previous hypotheses of character evolution among basal members of Teleostei, with implications for holostean character evolution. The synapomorphies shared by crown-group Teleostei appeared stepwise more than 140 million years ago over many speciation events and did not arise in a single ancestral species. The analyses of character distribution reflect the gradual accumulation of features that diagnose the crown group.</p> <p>http://zoobank.org/urn:lsid:zoobank.org:pub:0CBDA307-1DD5-4D18-A539-F066E7BF13DC</p> <p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at <a href="http://www.tandfonline.com/UJVP" target="_blank">www.tandfonline.com/UJVP</a></p> <p>Citation for this article: Arratia, G. 2017. New Triassic teleosts (Actinopterygii, Teleosteomorpha) from northern Italy and their phylogenetic relationships among the most basal teleosts. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2017.1312690.</p

The varasichthyid and other crossognathiform fishes, and the Break-up of Pangaea

<p>Crossognathiforms have been traditionally considered typical marine Cretaceous forms widely represented in the Northern Hemisphere and by a few members in Brazil. During the last 30 years they have been interpreted as Teleostei <em>incertae sedis</em>, clupeocephalans or a non-monophyletic group. New evidence indicates that the Oxfordian taxon <em>Chongichthys</em> (previously considered a Teleostei <em>incertae sedis</em> or a clupeocephalan), the Late Jurassic family Varasichthyidae (interpreted as basal teleosts), and the crossognathoids and pachyrhizodontoids form a clade here recognized as the Crossognathiformes. Varasichthyids are the sister group of a clade including <em>Chongichthys</em> (at the base) and crossognathoids+pachyrhizodontoids. The Crossognathiformes (including Varasichthyidae and <em>Chongichthys</em>) are basal teleosts placed between the Late Jurassic basal genera <em>Tharsis</em> and <em>Ascalabos</em> in one tree or between <em>Ascalabos</em> and the ichthyodectiforms in the second tree. The position of elopomorphs as the most basal extant teleosts is confirmed. A new interpretation of the phylogenetic position of the clade [<em>Humbertia</em>+[<em>Erichalcis</em>+[<em>Leptolepides</em>+<em>Orthogonikleithrum</em>]]], at the base of clupeocephalans, is suggested. </p> <p>The presence of the Late Jurassic varasichthyids (e.g. <em>Domeykos</em>) in South America (Chile) and Central America (Cuba; <em>Luisichthys</em>), and <em>Chongichthys</em> (Chile), and of the Late Jurassic genera <em>Ascalabos</em> and <em>Tharsis</em> and the ichthyodectiforms (e.g. <em>Allothrissops</em>) in Europe (e.g. Germany) allows the proposal of a sister-area relationship between Chile and Cuba, which was the sister area of Germany during the Late Jurassic. The Late Jurassic connection between the Palaeopacific (Chilean region) and the Tethys Sea (southern Germany) was through the newly formed Central Atlantic Ocean (Cuban region) as a result of the break up of Pangaea and separation of North America, South America and Africa. </p

A new fossil actinistian from the Early Jurassic of Chile and its bearing on the phylogeny of Actinistia

<div><p>ABSTRACT</p><p>We present the description and taxonomic reassignment of a new genus and species, <i>Atacamaia solitaria</i>, gen. et sp. nov., from Lower Jurassic strata of northern Chile, South America. The fish was previously reported as a new genus of Mawsoniidae, based on one unprepared specimen. The fish is characterized by a combination of numerous intriguing characters, such as the presence of a broad parietal bone partially covered laterally by a series of a few large supraorbital bones, a series of sclerotic bones, a lachrymojugal expanded anteriorly and markedly angled, and a metapterygoid with a well-developed ventral process that is ventral to the dorsal margin of the pterygoid plate. Addition of <i>Atacamaia</i> to previously published matrices produces unexpected collapses of certain nodes in the currently accepted phylogenetic hypothesis of Actinistia, creating many polytomies in the consensus tree. Our cladistic analysis suggests that <i>Atacamaia</i>, gen. et sp. nov., <i>Axelia</i>, and <i>Wimania</i> are closely related and together with <i>Piveteauia, Guizhoucoelacanthus</i>, and <i>Whiteia</i> are members of the order Coelacanthiformes. Based on previous analyses and our results, we recognize this grouping as the family Whiteiidae. Members of Whiteiidae are Triassic forms, except <i>Atacamaia solitaria</i>, gen. et sp. nov., from the Early Jurassic. The new fossil actinistian represents the youngest member of the family and the first discovered on the Paleopacific side of Gondwana; all other members are from China, Madagascar, and Spitsbergen. After comparison of previous hypotheses, we review the higher level taxonomy of Actinistia concerning the monophyly of Coelacanthiformes, Latimeroidei, Mawsoniidae, and Latimeriidae and propose a family diagnosis for Whiteiidae.</p><p>http://zoobank.org/urn:lsid:zoobank.org:pub:1CE8B66D-30D2-44EB-87EF-882628478C3B</p><p>SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP</p></div

Morphological and taxonomic descriptions of a new genus and species of killifishes (Teleostei: Cyprinodontiformes) from the high Andes of northern Chile

<div><p>A new genus and species, <i>Pseudorestias lirimensis</i>, is described from the southern part of the Chilean Altiplano. While sharing several characters that clearly align the new species with <i>Orestias</i>, this new fish is characterized by numerous autapomorphies: the Meckel cartilage is a continuous cartilage that broadly expands posteriorly (in large specimens, it keeps its anterior part and is resorbed posteriorly), the basibranchials are fused into one long element, the second pharyngobranchial is not displaced dorsally over pharyngobranchial tooth plate 3+4, but they are aligned, the anterior and posterior ceratohyals are closely articulated keeping a scarce amount of cartilage between both bones and ventral to them, ossified middle and distal dorsal radials are present in females as well as ossified middle and distal anal radials. <i>Pseudorestias lirimensis</i> presents strong sexual dimorphism associated to size. Females are almost twice as large and long than males, neuromast lines are absent in males, a mesethmoid is present in males, squamation on head is reduced in males, and ossified middle and distal radial of dorsal fin are cartilaginous in males. <i>Pseudorestias</i> and <i>Orestias</i> are suggested as the sole members of the tribe Orestiini. A list of characters diagnosing the tribe is provided. The presence of the new genus is interpreted as a possible result of the ecosystem isolation where the fish is living from surrounding basins—as early as possibly from the Miocene-Pliocene times—and its physical and chemical characteristics. Small populations, living conditions, small habitat, and reduced distribution make this species a strong candidate to be considered critically endangered, a situation already established for all other Chilean species living in the Altiplano. There is high probability it will become extinct due to water demands and climate change in the region.</p></div

sequence alignment

sequence alignmen

Diagrammatic representation of the neuromast lines and fields in orestiinids.

<p>Abb.: <b>a.no</b>, anterior nostril; <b>eth.sup.nl</b>, ethmoid-supraorbital neuromast line; <b>if.nl</b>, infraorbital neuromast line; <b>m.nl</b>, middle neuromast line; <b>op.nl</b>, opercular line; <b>p.no</b>, posterior nostril; <b>pop-m.nl</b>, preopercular-mandibular line; <b>ro.nl</b>, rostral neuromast line. Small arrowheads point to small fields of neuromasts.</p

Karyotype of <i>Pseudorestias lirimensis</i> gen. et sp. nov.

<p>Abb.: <b>M-SM</b>, metacentric-submetacentric chromosomes; <b>ST-T</b>, subtelocentric-telocentric chromosomes.</p

Articulation of the lower jaw with quadrate and position of Meckel’s cartilage.

<p>Females of 61.73 mm SL and 63.8 mm SL (KUNHM 41384). <b>A</b>, posterior part of jaw in lateral view and its articulation with quadrate. Note the contribution of the retroarticular as part of the articular fossa. <b>B</b>, jaw in medial view illustrating the Meckel cartilage. Abb.: <b>ang-ar</b>, anguloarticular; <b>de</b>, dentary; <b>M.car</b>, Meckel’s cartilage; <b>nt</b>, notch; <b>qu</b>, quadrate; <b>pv.pr</b>, posteroventral process; <b>rar</b>, retroarticular.</p

Cephalic neuromast lines and squamation patterns (colored areas) of <i>Pseudorestias lirimensis</i> gen. et sp. nov.

<p><b>A</b>, head in lateral view (female, 61.7 mm SL; KUNHM 41384). <b>B</b>, head in lateral view (male, 30 mm SL; KUNHM 41384). <b>C</b>, head in dorsal view (female, 61.7 mm SL). <b>D</b>, head in dorsal view (male, 30 mm SL). Abb.: <b>a.no</b>, anterior nostril; <b>eth.sup.nl</b>, ethmoid-supraorbital neuromast line; <b>if.nl</b>, infraorbital neuromast line; <b>m.nl</b>, middle neuromast line; <b>op.nl</b>, opercular line; <b>p.no</b>, posterior nostril; <b>pop-m.nl</b>, preopercular-mandibular line; <b>ro.nl</b>, rostral neuromast line.</p

Braincase in ventral view in <i>Pseudorestias lirimensis</i> (KUNHM 41384, female of 63.8 mm SL).

<p>Abbr.: <b>a.hy1</b>, fossa for articulation of the anterior condyle of hyomandibula; <b>a.hy2</b>, fossa for articulation of the posterior condyle of the hyomandibula; <b>boc</b>, basioccipital; <b>ep</b>, epiotic; <b>eth.c</b>, ethmoid or rostral cartilage; <b>fr</b>, frontal bone; <b>l.eth</b>, lateral ethmoid; <b>par</b>, parasphenoid; <b>pro</b>, prootic; <b>pt</b>, pterotic; <b>sph</b>, sphenotic.</p