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The Sulphur Mountain Formation in Alberta, Canada, comprises shales, siltstones, and limestones laid down on the continental shelf and shoreline along the western margin of the North American Craton during the Early and Middle Triassic. At least 13 taxa of fossil marine fishes have been found at a number of Triassic localities along the Front Ranges and foothills in Alberta. Common taxa (Boreosomus, Birgeria, Bobasatrania, Australosomus, Saurichthys, parasemionotids, and coelacanths) found at localities in Alberta are similar to those found at the classic Lower and Middle Triassic localities near Wapiti Lake, British Columbia, and in East Greenland, Spitzbergen, Madagascar, and China. The occurrence of Lower Triassic fishes in western Alberta shows that this fauna was widespread, occurring over at least 1000 km of shoreline, and that ecological and environmental factors were similar along the western edge of the Panthalassic Ocean during the Early Triassic. La Formation de Sulphur Mountain en Alberta (Canada) comprend des shales et calcaires deposes sur la plateforme continentale et le littoral le long de la marge occidentale du craton nord-americain, durant le Trias precoce et moyen. Au moins 13 taxons de poissons marins fossiles ont ete trouves en differentes localites triasiques le long des chainons frontaux et des contreforts des Rocheuses en Alberta. Des taxons repandus (Boreosomus, Birgeria, Bobasatrania, Australosomus, Saurichthys, parasemionotides et crelacanthes) trouves dans des localites en Alberta sont semblables a ceux observes dans les localites classiques du Trias inferieur et moyen pres du lac Wapiti (Colombie-Britannique) et dans l'est du Groenland, au Spitzberg, a Madagascar et en Chine. La presence de poissons du Trias inferieur dans l'ouest de l'Alberta montre que cette faune etait repandue, couvrant au moins 1000 km de littoral, et que des facteurs ecologiques et environnementaux semblables prevalaient le long de la bordure ouest de l'ocean Panthalassique durant le Trias precoce. [Traduit par la Redaction], Introduction For over 100 years well-preserved Triassic fishes have been collected from Alberta, Canada, beginning with the first specimen discovered by E.W. Peyto from Banff, and sent by the curator [...]

Myledaphus bipartitus is a Late Cretaceous (75 Ma) freshwater guitarfish, commonly represented by teeth and vertebral centra. The species was first described in 1876, but until now, very little has been known about its ecology and life history. We analyzed the age and growth using 117 fossilized centra (74 hemisectioned) from the Oldman and Dinosaur Park formations of southern Alberta. The resulting estimated maximum age was 16 years. Radial distance (RD) at the estimated asymptotic growth was calculated, and average RD at birth and 3 years were compared with two extant marine species of Rhinobatos (R. productus and R. rhinobatos). Birth ring size ranged from 0.9 to 1.8 mm RD. At age three, centrum RD was between 2.8 and 4.6 mm RD for M. bipartitus and significantly less than R. productus and R. rhinobatos (5.0-6.6 mm RD). Myledaphus approached 'asymptotic' growth at 7.8 mm RD in the growth equation. The growth trajectory of Myledaphus had a similar slope to the Rhinobatos species, but with significantly smaller centrum RD. Rhinobatos rhinobatos also outlived Myledaphus by 8 years. Myledaphus bipartitus est un poisson-guitare d'eau douce du Cretace tardif (75 Ma) communement represente par des dents et des centres vertebraux. L'espece a ete decrite pour la premiere fois en 1876, mais jusqu'a present, les connaissances sur son ecologie et son cycle de vie etaient tres limitees. Nous en avons analyse l'age et la croissance a la lumiere de 117 centres fossilises (74 hemisectionnes) des Formations d'Oldman et de Dinosaur Park du sud de l'Alberta. L'age maximum ainsi estime etait de 16 ans. La distance radiale (RD) au taux de croissance asymptotique estime a ete calculee, et les RD moyennes a la naissance et a trois ans ont ete comparees a celles de deux especes marines actuelles de Rhinobatos (R. productus et R. rhinobatos). La taille des anneaux a la naissance, en termes de RD, va de 0,9 mm a 1,8 mm. A 3 ans, la RD des centres va de 2,8 mm a 4,6 mm pour M. bipartitus et est significativement plus faible que celles de R. productus et R. rhinobatos (RD de 5,0-6,6 mm). Myledaphus s'approche de la croissance << asymptotique >> a une RD de 7,8 mm dans l'equation de croissance. La trajectoire de croissance de Myledaphus presente une pente semblable a celle des especes de Rhinobatos, bien qu'avec des RD des centres significativement plus faibles. La duree de vie de Rhinobatos rhinobatos surpasse egalement de 8 ans celle de Myledaphus. [Traduit par la Redaction], Introduction Myledaphus bipartitus, Cope, 1876, is a Late Cretaceous enigmatic freshwater batoid represented predominantly by isolated teeth (Cappetta 2012). It is known from various Campanian formations such as the Oldman [...]

Horseshoeichthys armaserratus, gen. et sp. nov., (Clupeomorpha: Ellimmichthyiformes: Sorbinichthyidae) is described from the Horseshoe Canyon Formation (Maastrichtian), Albertosaurus bonebed locality, Alberta, Canada. Horseshoeichthys armaserratus is classified as an ellimmichthyiform based on the following characters: the presence of a sixth infraorbital with a sensory canal that leads to the fifth infraorbital, absence of a supraorbital bone, subrectangular predorsal scutes, parietals in contact with each other at the midline, and two supramaxillae. The specimen is classified in the Sorbinichthyidae Family as it has abdominal ribs articulating in pits on the centra, posterior spines on predorsal scutes, and absence of a median spine on predorsal scutes. A new genus and species is proposed based on the presence of (anteriorly) Y-shaped mesethmoid, supraorbital, subrectangular predorsal scutes with coarse, rounded serrae on the posterior margin and a large anterior projection, scales with serrae on the circuli, and two postcleithra. This specimen represents the first freshwater ellimmichthyiform from the Upper Cretaceous of North America and the highest paleolatitude (59°N) occurrence known for the family. Furthermore, the dentary and centra have distinctive morphologies that are matched by specimens in microvertebrate localities from three underlying formations, including the Milk River Formation (Santonian), which indicates at least a 14 million year history for this lineage. Horseshoeichthys armaserratus, gen. et sp. nov., (Clupeomorpha: Ellimmichthyiformes: Sorbinichthyidae), de la localite du gisement d'ossements d'Albertosaurus de la Formation de Horseshoe Canyon (Maastrichtien), en Alberta, au Canada, est decrit. Horseshoeichthys armaserratus est affecte aux ellimmichthyiformes a la lumiere des caracteres suivants : la presence d'un sixieme sous-orbitaire presentant un canal sensoriel qui mene au cinquieme sous-orbitaire, l'absence d'un os sus-orbitaire, des plaques osseuses pre-dorsales sub-rectangulaires, des parietaux en contact les uns avec les autres au niveau de la ligne meediane et deux sus-maxillaires. Le specimen est affecte aux sorbinichthyides puisqu'il presente des cotes abdominales s'articulant dans des fosses sur le centrum et des eepines posteerieures sur les plaques osseuses pre-dorsales, et que ces dernieres n'ont pas d'eepine meediane. Un nouveau genre et une nouvelle espece sont proposesa la lumiere de la presence d'un meesethmolde (anterieurement) en forme de Y, d'un sus-orbitaire, de plaques osseuses pre- dorsales sub-rectangulaires presentant des stries arrondies et epaisses sur leur bord libre posterieur et une grande projection anterieure, d'ecailles avec des stries sur le circulus et de deux postcleithra. Ce specimen represente le premier ellimmichthyiforme d'eau douce du Cretace superieur de l'Ameerique du Nord et l'exemple connu de cette famille provenant de la plus haute paleolatitude (59°N). En outre, le dentaire et le centrum presentent des morphologies particulieres semblables a celles de specimens trouvees dans des localitees de microvertebres de trois formations sous-jacentes, dont la Formation de Milk River (Santonien), ce qui indique une histoire d'au moins 14 millions d'annees pour cette lignee. [Traduit par la Redaction], Introduction Ellimmichthyiformes are an extinct order of double-armored non-clupeiform clupemorphs with taxa that inhabited both marine and freshwater environments (Grande 1985; Hay et al. 2007; Alvarado-Ortega et al. 2008). Ellimmichthyiforms [...]

Sauropterygia, one of the main clades of Mesozoic marine reptiles, diversified shortly after the Permo-Triassic biotic crisis and afterwards remained one of the major components of Early Triassic and later Mesozoic marine ecosystems. On the other hand, actual specimens of marine reptiles of Olenekian age are still rare in the fossil record, coming only from a few localities worldwide. Here we describe associated remains of a larger marine reptile of around 4 m body length, with nothosauroidean affinities from the Sulphur Mountain Formation exposed at the L cirque locality of Wapiti Lake area in British Columbia. Although the specimen records only scattered parts of the posterior vertebral column, some gastral ribs and most notably, the proximal portion of one hind limb together with a fan-shaped ischium, it represents one of the oldest records of Sauropterygia and larger representatives of aff. Nothosauroidea specifically, as well as the northernmost occurrence of such animals in the Triassic. As such, the new specimen is important for understanding the biogeography and early evolution of the group and that of Sauropterygia, in general. [ABSTRACT FROM AUTHOR]

Fossil material from the Maastrichtian part of the Scollard Formation is identified as belonging to an acanthomorph fish. An articulated specimen, preserved in part and counterpart, is a member of the paracanthopterygian order Percopsiformes, based on it having a full neural spine on the second preural centrum and two epurals in the caudal skeleton (both paracanthopterygian characters), as well as six branchiostegal rays and an anterodorsal excavated margin on the opercle (percopsiform characters). We name this as a new genus and species, Lindoeichthys albertensis. A phylogenetic analysis with no prior constraints recovered a single most-parsimonious tree with the new taxon placed as the sister group to a clade containing the Palaeocene Montana genus Mcconichthys + Percopsidae. However, this analysis did not recover the traditional percopsiforms (including Aphredoderidae and Amblyopsidae) as monophyletic. A second analysis, in which we constrained the traditional members of the Percopsiformes to be monophyletic, resulted in the new species being placed as the sister group to Percopsis. The articulated percopsiform specimen from the Pisces Point locality allows isolated dentaries from vertebrate microfossil localities to be identified as being from a member of that group. These isolated elements first appear in the late Campanian Judith River Group of Alberta and the Kaiparowits Formation of Utah, documenting that percopsiform fishes were present in the Western Interior of North America at least 75 Ma ago. [ABSTRACT FROM AUTHOR]

Sauropterygia, one of the main clades of Mesozoic marine reptiles, diversified shortly after the Permo-Triassic biotic crisis and afterwards remained one of the major components of Early Triassic and later Mesozoic marine ecosystems. On the other hand, actual specimens of marine reptiles of Olenekian age are still rare in the fossil record, coming only from a few localities worldwide. Here we describe associated remains of a larger marine reptile of around 4 m body length, with nothosauroidean affinities from the Sulphur Mountain Formation exposed at the L cirque locality of Wapiti Lake area in British Columbia. Although the specimen records only scattered parts of the posterior vertebral column, some gastral ribs and most notably, the proximal portion of one hind limb together with a fan-shaped ischium, it represents one of the oldest records of Sauropterygia and larger representatives of aff. Nothosauroidea specifically, as well as the northernmost occurrence of such animals in the Triassic. As such, the new specimen is important for understanding the biogeography and early evolution of the group and that of Sauropterygia, in general. [ABSTRACT FROM AUTHOR]

The replacement names Homalodontus nom. nov. ( Homalodontidae nom. nov.) are proposed for the Early Triassic shark Wapitiodus Mutter et al., 2007 (Wapitiodidae Mutter et al., 2007), preoccupied by the Triassic conodont Wapitiodus Orchard, 2005 (Gondolellidea Lindström, 1970 ). © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 154, 419–420. [ABSTRACT FROM AUTHOR]