Characterization of coelacanth scales from the early cretaceous freshwater locality of las hoyas, upper Barremian (Cuenca, Spain)

Coelacanths are rare, mostly marine fishes, but the species from the Lower Cretaceous Spanish locality of Las Hoyas (Barremian) is a freshwater form and we know almost nothing about it. The Las Hoyas specimens are very rare and relatively incomplete, but there are still many things we can learn from the isolated skeletons and scales. First, the coelacanth scales were distinguished from other superficially similar scales (i.e., other “amioid” scales). Coelacanth scales are distinguished by the presence of a smooth central surface, a particular pattern of arrangement of concentric growth cessation marks, and mainly a relatively short posterior field with thick elongated ridges. Only a few articulated coelacanth specimens have been recovered from Las Hoyas to date, and only 7.3% (n = 11) of the total isolated scales are coelacanth. The Las Hoyas coelacanth scales represent relatively large individuals. This suggests that a natural population of the coelacanth may have not inhabited permanently the freshwater pool represented by the excavated area of Las Hoyas because small juveniles should be the most common sizesFunding for this project comes from a grant “Ayudas a la Investigación de la Sociedad Española de Paleontología, 2015-2016” provided to H.M.-A. This paper is a contribution to project CGL-2013-42643 P (MINECO, Spain

Morphologic and Meristic Characteristics of Lacustrine Coarse Woody Structure as Fish Habitat

Riparian areas are inextricably linked to aquatic systems. In light of widespread riparian and littoral zone tree removal caused by logging, cottage development, and road development, more research needs to be done to assess the importance of woody structure as fish habitat. The objectives of this study are to: 1) quantify the morphology (e.g., branching complexity, length, etc.) of trees in lakes as it relates to physical habitat for fish, and 2) identify relations between species richness, diversity, abundance, and total length of individual fish species and the physical characteristics of submerged trees. Trees in Katherine Lake, Wisconsin were selected using random and random-stratified sampling. Tree morphology ( e.g., branching complexity, bole diameter, wet length, free board, clearance, minimum depth of tree, total water depth at tree, and bridging distance), general site habitat characteristics (e.g., distance to other coarse woody structure, site slope, mean depth, and dominant and subdominant particle sizes), and fish metrics (e.g., taxa richness, diversity, adult abundance, and adult total length) were quantified at each site. Conifers were found to be more abundant than deciduous trees in Katherine Lake and physically complex trees of either type were rare. Branching complexity in coniferous trees was highly correlated with bole diameter, wet length, and clearance, whereas, branching complexity in deciduous trees was highly correlated with wet length. A total of 16 species of fish utilized submerged wood as habitat. There were significantly more smallmouth bass (Micropterus dolomieu) and bluegill (Lepomis macrochirus) on sites with submerged wood compared to sites without submerged wood in Katherine Lake. Conifer trees had significantly higher numbers of schooling cyprinids (Cyprinidae), bluegill, and walleye (Stizostedian vitreum) when compared to deciduous trees. Fish taxa richness, diversity, and abundance increased in coniferous and deciduous trees that were morphologically more complex with greater amounts of fine branching. Complex trees were dominated by schooling cyprinids, rock bass (Ambloplites rupestris), smallmouth bass, bluegill, and yellow perch (Perca flavescens). Walleyes were common in complex conifers but not deciduous trees. Less complex trees appeared to attract greater numbers of young-of-the-year (YOY) smallmouth bass and YOY rock bass as opposed to adults of the same species. Adult black crappie and rock bass showed seasonal tendencies in moving off of CWS sites in late August. This study demonstrates that wood is important in lakes as fish habitat and continuous recruitment of new, more-complex trees from riparian areas is important to sustain the long-term ecological processes inherent to the riparian area-littoral zone ecotone. Ultimately, better policies need to be established in order to protect riparian vegetation, shoreline wood, and wood recruitment into lakes.Federal Aid in Sport Fish Restoration, Project F-95-

Earliest North American articulated freshwater acanthomorph fish (Teleostei: Percopsiformes) from Upper Cretaceous deposits of Alberta, Canada

© 2019 Cambridge University Press. 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

New articulated osteoglossomorph from Late Cretaceous freshwater deposits (Maastrichtian, Scollard Formation) of Alberta, Canada

© 2016, © by the Society of Vertebrate Paleontology. ABSTRACT: Articulated fishes are rare in Late Cretaceous non-marine deposits of the Western Interior; fishes are more often represented by disarticulated elements in vertebrate microfossil localities. A new Maastrichtian locality of the Scollard Formation in central Alberta, Canada, has been named Pisces Point to reflect the diversity of articulated fishes that are now being recovered from this site. Material collected from the Pisces Point locality includes a percopsiform, a semionotiform, at least one esociform, and at least two osteoglossomorphs. One of these is described here as a new genus and species, †Wilsonichthys aridinsulensis. A phylogenetic analysis shows this new taxon to be the sister group of most other Osteoglossiformes. The new articulated material allows us to identify some of the microfossil remains previously collected from other Late Cretaceous sites as belonging to the same or a similar taxon. http://zoobank.org/urn:lsid:zoobank.org:pub:C35449C0-5711-4618-9084-177ADA83FEE7 Citation for this article: Murray, A. M., M. G. Newbrey, A. G. Neuman, and D. B. Brinkman. 2016. New articulated osteoglossomorph from Late Cretaceous freshwater deposits (Maastrichtian, Scollard Formation) of Alberta, Canada. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2016.1120737

Characterization of coelacanth scales from the early cretaceous freshwater locality of las hoyas, upper Barremian (Cuenca, Spain)

© Sociedad Española de Paleontología ISSN 2255-0550. Coelacanths are rare, mostly marine fishes, but the species from the Lower Cretaceous Spanish locality of Las Hoyas (Barremian) is a freshwater form and we know almost nothing about it. The Las Hoyas specimens are very rare and relatively incomplete, but there are still many things we can learn from the isolated skeletons and scales. First, the coelacanth scales were distinguished from other superficially similar scales (i.e., other “amioid” scales). Coelacanth scales are distinguished by the presence of a smooth central surface, a particular pattern of arrangement of concentric growth cessation marks, and mainly a relatively short posterior field with thick elongated ridges. Only a few articulated coelacanth specimens have been recovered from Las Hoyas to date, and only 7.3% (n = 11) of the total isolated scales are coelacanth. The Las Hoyas coelacanth scales represent relatively large individuals. This suggests that a natural population of the coelacanth may have not inhabited permanently the freshwater pool represented by the excavated area of Las Hoyas because small juveniles should be the most common sizes

Cenomanian-Campanian (Late Cretaceous) mid-palaeolatitude sharks of Cretalamna appendiculata type

The type species of the extinct lamniform genus Cretalamna, C. appendiculata, has been assigned a 50 Ma range (Albian-Ypresian) by a majority of previous authors. Analysis of a partly articulated dentition of a Cretalamna from the Smoky Hill Chalk, Kansas, USA (LACM 128126) and isolated teeth of the genus from Cenomanian to Campanian strata of Western Australia, France, Sweden, and the Western Interior of North America, indicates that the name of the type species, as applied to fossil material over the last 50 years, represents a large species complex. The middle Cenomanian part of the Gearle Siltstone, Western Australia, yielded C. catoxodon sp. nov. and "Cretalamna" gunsoni. The latter, reassigned to the new genus Kenolamna, shares several dental features with the Paleocene Palaeocarcharodon. Early Turonian strata in France produced the type species C. appendiculata, C. deschutteri sp. nov., and C. gertericorum sp. nov. Cretalamna teeth from the late Coniacian part of the Smoky Hill Chalk in Kansas are assigned to C. ewelli sp. nov., whereas LACM 128126, of latest Santonian or earliest Campanian age, is designated as holotype of C. hattini sp. nov. Early Campanian deposits in Sweden yielded C. borealis and C. sarcoportheta sp. nov. A previous reconstruction of the dentition of LACM 128126 includes a posteriorly situated upper lateroposterior tooth, with a distally curved cusp, demonstrably misplaced as a reduced upper "intermediate" tooth. As originally reconstructed, the dentition resembled that of cretoxyrhinids (sensu stricto) and lamnids. Tooth morphology, however, indicates an otodontid affinity for Cretalamna. The root is typically the most diagnostic feature on an isolated Cretalamna tooth. This porous structure is commonly abraded and/or corroded and, consequently, many collected Cretalamna teeth are indeterminable at species level