Fossil Fish Research Papers - Academia.edu (original) (raw)

The newly collected shark and ray tooth fossils from the marine sediments of the Upper Marine Molasse close to Allerding (4.8 km SE of Schärding, Austria) allow for a review of the hitherto known diversity comprising a taxonomic update... more

The newly collected shark and ray tooth fossils from the marine sediments of the Upper Marine Molasse close to Allerding (4.8 km SE of Schärding, Austria) allow for a review of the hitherto known diversity comprising a taxonomic update and the documentation of additional taxa. Besides ten taxa already known from the area, the following taxa were collected for the first time from the site:

Remains of the odd fossil teleost Cylindracanthus from the Upper Cretaceous (Campanian and Maastrichtian) of northern germany are reported.

The evolution of fishes to tetrapods (four-limbed vertebrates) was one of the most important transformations in vertebrate evolution. Hypotheses of tetrapod origins rely heavily on the anatomy of a few tetrapod-like fish fossils from the... more

The evolution of fishes to tetrapods (four-limbed vertebrates) was one of the most important transformations in vertebrate evolution. Hypotheses of tetrapod origins rely heavily on the anatomy of a few tetrapod-like fish fossils from the Middle and Late Devonian period (393-359 million years ago) 1. These taxa-known as elpistostegalians-include Panderichthys 2 , Elpistostege 3,4 and Tiktaalik 1,5 , none of which has yet revealed the complete skeletal anatomy of the pectoral fin. Here we report a 1.57-metre-long articulated specimen of Elpistostege watsoni from the Upper Devonian period of Canada, which represents-to our knowledge-the most complete elpistostegalian yet found. High-energy computed tomography reveals that the skeleton of the pectoral fin has four proximodistal rows of radials (two of which include branched carpals) as well as two distal rows that are organized as digits and putative digits. Despite this skeletal pattern (which represents the most tetrapod-like arrangement of bones found in a pectoral fin to date), the fin retains lepidotrichia (fin rays) distal to the radials. We suggest that the vertebrate hand arose primarily from a skeletal pattern buried within the fairly typical aquatic pectoral fin of elpistostegalians. Elpistostege is potentially the sister taxon of all other tetrapods, and its appendages further blur the line between fish and land vertebrates. The first tetrapods known from skeletal remains date back to the Late Devonian period (about 374 million years ago) 6,7 , while trackway fossils showing digitate impressions of limbs suggest an earlier origin for this clade 8. Over the past decade, fossils that provide information on the fish-to-tetrapod transition have been used to better understand anatomical transformations associated with locomotion 5,9-12 , breathing 13 , hearing 14 and feeding 11,15 , with regard to the change in habitat from water to land. Until now, the terrestrialization of vertebrates has primarily been a matter of comparing six relatively well-known Devonian taxa among stem-group tetrapods 16 : a true piscine sarcopterygian, Eusthe-nopteron foordi; a piscine elpistostegalian, Panderichthys rhombolepis; a near-tetrapod elpistostegalian, Tiktaalik roseae; and three true basal tetrapods, Acanthostega gunnari, Ventastega curonica and Ichthyostega sp. Here we adopt an apomorphy-based definition of tetrapods as 'all organisms derived from the first sarcopterygian to have possessed digits homologous with those in Homo sapiens' 17,18. However, these inferences regarding terrestrialization rely critically on the handful of specimens that have been referred to elpistostega-lians, none of which has been completely described. The postcranial anatomy of Panderichthys is primarily restricted to the morphology of the pectoral fins and girdle 2,19,20 , the vertebrae 2,21 , the scale patterning 22 and very little on the pelvic fin and girdle morphology 9. Although more than 60 specimens 1,10 of Tiktaalik have been found, most of the anatomy of this species has been described from a fairly complete individual for which the skull 1,15 , pectoral and pelvic fins and girdles 5,10,23 , scales 22 and the trunk region 1 anterior to the pelvic region are preserved.

The paired symphyseal tooth whorls of the Carboniferous chondrichthyan Edestus are perhaps the most enigmatic dental structures of any known vertebrate. The tooth whorls have been compared to scissors or to saw blades. It is commonly held... more

The paired symphyseal tooth whorls of the Carboniferous chondrichthyan Edestus are perhaps the most enigmatic dental structures of any known vertebrate. The tooth whorls have been compared to scissors or to saw blades. It is commonly held that the tooth whorls were used in opposition, to cut prey caught between them. However, the curvature of the whorls makes such a function inefficient and therefore implausible. A symphyseal tooth of Edestus minor from the Pennsylvanian of Texas provides the first new information bearing on the function of Edestus tooth whorls in over a century. The tooth is truncated apically, and the surface of the surviving portion is worn smooth. The orientation of the abraded surface, perpendicular to the axis of the crown, suggests that the tooth whorls were used to slash prey with a vertical motion of the anterior part of the body. Such a mode of predation apparently has not been reported in any other organism, extinct or extant. In contrast to Edestus, wear to the symphyseal teeth of Helicampodus is to the sides of the crowns, probably resulting from contact with the opposing dentition. Unpublished notes of W. Langston, Jr. (1921–2013) on the interpretation of the Edestus tooth from Texas are discussed.

Late Pennsylvanian age deposits in the Velebit Mts and Lika region of Croatia are mainly marine, but also include relative thin terrestrial intercalations yielding diverse fossil floras. A revision of the fossil floras, based on about 200... more

Late Pennsylvanian age deposits in the Velebit Mts and Lika region of Croatia are mainly marine, but also include relative thin terrestrial intercalations yielding diverse fossil floras. A revision of the fossil floras, based on about 200 specimens in the collections of the Croatian Natural History Museum (Zagreb) and National Museum (Prague), has revealed 19 species, strongly dominated by medullosaleans, sphenophytes and marattialean ferns. These fossils represent the remains of the lowland vegetation that was growing on the southern side of the Variscan Mountains, and can be compared with similar floras found in northern Spain and the Carnic Alps. Similar aged floras also occurred in intramontane sequences further north and west in Europe but these often tend to be dominated by marattialean ferns and cordaitaleans rather than alethopterid medullosaleans as in the Croatian floras. These differences are probably the result of the higher elevation and better drainage of the intramontane basins. Biostratigraphically the Croatian floras belong to the S. angustifolium Zone of Stephanian B (late Kasimovian or earliest Gzhelian) age. •

The fossil record of early vertebrates has been influential in elucidating the evolutionary assembly of the gnathostome bodyplan. Understanding of the timing and tempo of vertebrate innovations remains, however, mired in a literal reading... more

The fossil record of early vertebrates has been influential in elucidating the evolutionary assembly of the gnathostome bodyplan. Understanding of the timing and tempo of vertebrate innovations remains, however, mired in a literal reading of the fossil record. Early jawless vertebrates (ostracoderms) exhibit
restriction to shallow-water environments. The distribution of their stratigraphic occurrences therefore reflects not only flux in diversity, but also secular variation in facies representation of the rock record. Using stratigraphic, phylogenetic and palaeoenvironmental data, we assessed the veracity of the fossil records of the jawless relatives of jawed vertebrates (Osteostraci, Galeaspida, Thelodonti, Heterostraci).Non-randommodels of fossil recovery potential using Palaeozoic sea-level changes were used to calculate confidence intervals of clade origins. These intervals extend the timescale for possible origins into the Upper
Ordovician; these estimates ameliorate the long ghost lineages inferred for Osteostraci, Galeaspida andHeterostraci, given their known stratigraphic occurrences and stem–gnathostome phylogeny. Diversity changes through the Silurian and Devonian were found to lie within the expected limits predicted from estimates of fossil record quality indicating that it is geological, rather than biological factors, that are responsible for shifts in diversity. Environmental restriction also appears to belie ostracoderm extinction and demise rather than competition with jawed vertebrates.

A new record of fossil chondrichthyan tooth was found from a float of the Early Permian limestone block of the Omama complex of the Ashio tectonic belt, Kiryu City, Gunma Prefecture, central Japan. The specimen (GMNH-PV-2405) is composed... more

A new record of fossil chondrichthyan tooth was found from a float of the Early Permian limestone block of the Omama complex of the Ashio tectonic belt, Kiryu City, Gunma Prefecture, central Japan. The specimen (GMNH-PV-2405) is composed of a flattened root with a median cusp. Though the lingual side of the root (base) is broken, the basolabial shelf is recognized in a labial rim of its radical side. The basolabial shelf is weakly disrupted. The median cusp inclines distally. It has a tall triangular shape with fine striations in the radical half of the lingual surface. The shape of the cusp cross section is convex on its lingual surface. The presence of lateral cusps and intermediate cusplets is uncertain. Through the combination of some characteristics, GMNH-PV-2405 is identified as Ctenacanthidae gen. et sp. indet. GMNH-PV-2405 marks the second record of Paleozoic vertebrate fossils from Gunma Prefecture, and the fifth vertebrate remains from the Ashio tectonic belt. The occurrence of GMNH-PV-2405 provides important paleontological information regarding the paleogeographical setting of the Ashio tectonic belt in the late Paleozoic, and also the radiation in the oceanic environment of the ctenacanthiform shark.

A partial skull collected in the Mancos Shale northwest of Grand Junction, Mesa County, Colorado, represents the first specimen of the ichthyodectid fish Xiphactinus audax reported from the formation in western Colorado. The Museum of... more

A partial skull collected in the Mancos Shale northwest of Grand Junction, Mesa County, Colorado, represents the first specimen of the ichthyodectid fish Xiphactinus audax reported from the formation in western Colorado. The Museum of Western Colorado specimen is from the Smoky Hill Member of the Mancos and is likely Coniacian or Santonian in age. The specimen is well preserved and consists of both premaxillae, the left maxilla, a fragment of the right maxilla, both dentaries, a ceratohyal, another indeterminate skull bone, two vertebrae, several fragments of pectoral fin spines, numerous rib and vertebral spine fragments, and nearly 400 scales. The only other Xiphactinus specimens from the Mancos Shale are a partial skeleton from near Snowmass, Colorado, at the Denver Museum of Nature and Science and very fragmentary field evidence from near Green River, Utah. All three occurrences of Xiphactinus in the Mancos Shale in Colorado and Utah (plus recent reports from the Tropic Shale of Utah) are unreported in previous summaries of the genus but push the distribution of Xiphactinus farther west in its southern distribution.

This paper contains a collection of 722 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly... more

This paper contains a collection of 722 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2018. The list is the result of regular queries in numerous journals, books and online publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2018, list of descriptions of extinct and extant species from 2018, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide data information on the geographic and depth distribution of newly described species, i.e. the type specimens from the years 1990 to 2018 in a hot spot analysis. The subheader "biodiversity" comprising a complete list of all valid chimaeriform, selachian and batoid species, as well as a list of the top 20 most researched chondrichthyan species. Please note that the content of this paper has been compiled to the best of our abilities based on current knowledge and practice, however, possible errors cannot entirely be excluded.

This paper contains a collection of 817 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly... more

This paper contains a collection of 817 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2017. The list is the result of regular queries in numerous journals, books and online publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2017, list of descriptions of extinct and extant species from 2017, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide data information on the geographic and depth distribution of newly described species, i.e. the type specimens from the years 1990 to 2017 in a hot spot analysis. New in this year's POTY is the subheader "biodiversity" comprising a complete list of all valid chimaeriform, selachian and batoid species, as well as a list of the top 20 most researched chondrichthyan species.

This paper contains a collection of 807 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly... more

This paper contains a collection of 807 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2019. The list is the result of regular queries in numerous journals, books and online publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2019, list of descriptions of extinct and extant species from 2019, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide data information on the geographic and depth distribution of newly described species, i.e. the type specimens from the years 1990 to 2019 in a hot spot analysis. The subheader "biodiversity" comprising a complete list of all valid chimaeriform, selachian and batoid species, as well as a list of the top 20 most researched chondrichthyan species.

This paper contains a collection of 803 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly... more

This paper contains a collection of 803 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2016. The list is the result of regular queries in numerous journals, books and online publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2016, list of descriptions of extinct and extant species from 2016, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide information on the geographic and depth distribution of newly described species, i.e. the type specimens from the year 1990- 2016 in a hot spot analysis.
Please note that the content of this paper has been compiled to the best of our abilities based on current knowledge and practice, however, possible errors cannot entirely be excluded.

Sobre la vieja del agua fósil bautizada Podgorny

Mass extinction events near the Palaeozoic/Mesozoic boundary had a major impact on life on Earth. Here we present an updated analysis of the diversity dynamics and size changes of Chondrichthyes and Osteichthyes during the... more

Mass extinction events near the Palaeozoic/Mesozoic boundary had a major impact on life on Earth. Here we present an updated analysis of the diversity dynamics and size changes of Chondrichthyes and Osteichthyes during the Permian/Triassic. We show that chondrichthyan genus diversity declined during the Middle–Late Permian. Many Palaeozoic groups (e.g. Petalodontiformes) were largely replaced by hybodonts and modern sharks (Neoselachii). A significant overall decrease in tooth size and body length observed across the Permian/Triassic boundary suggests a selective loss of large-sized chondrichthyans. The largest extinction occurred amongst marine groups, with benthic and pelagic groups suffering most, but selectivity for these palaeoecological traits is not evident. Osteichthyes show a general pattern of low diversity during the Permian to higher levels in the Triassic, leading to increased diversity among the modern ray-finned fishes (Neopterygii). Palaeopterygii experienced a significant increase in body size across the Middle/Late Permian boundary and remain among the larger fishes during the Triassic. Neopterygians mostly remained smaller and, thus, mostly occupied lower positions within aquatic food webs. Our data indicates an important evolutionary turnover among fishes, changing from chondrichthyan-dominated communities of the Carboniferous–Permian to osteichthyan (actinopterygian)-dominated associations of the Meso- and Cenozoic.

The osteology of the ichthyodectiform Eubiodectes libanicus (Pictet & Humbert, 1866) from the Cenomanian of Lebanon is described on the basis of acid-prepared specimens. For comparative purposes, the osteology of other putative... more

The osteology of the ichthyodectiform Eubiodectes libanicus (Pictet & Humbert, 1866) from the Cenomanian of Lebanon
is described on the basis of acid-prepared specimens. For comparative purposes, the osteology of other putative ichthyodectiforms is described or discussed. We focus on the description of hitherto poorly described species such as Chiromystus mawsoni Cope, 1885, Ghrisichthys bardacki (Cavin, 1997a), ‘Saurodon’ intermedius (Newton, 1878) and Thrissops sp.
from Kimmeridge, England. Sixty-nine morphological characters are defined and analysed to infer the phylogenetic relationships
within ichthyodectiforms. The main results are: (1) exclusion of Ascalabothrissops and Pachythrissops from the ichthyodectiforms; (2) redesignation of ‘Ichthyodectes’ bardacki, from the Turonian of Morocco, to Ghrisichthys gen. nov.; (3) resolution of a monophyletic family Cladocyclidae grouping mid-Cretaceous ichthyodectiforms that lived mainly along
the southern margin of Tethys (Chirocentrites, Cladocyclus, Eubiodectes, Chiromystus); (4) resolution of a Late Cretaceous
family Ichthyodectidae containing Ichthyodectes, Ghrisichthys and Xiphactinus from mid-northern latitude seas; and (5) a
better resolved Late Cretaceous family Saurodontidae in the northern hemisphere, that includes the genus Gillicus.

Since the first time a Megalodon shark tooth was found and identified as such, the question of the actual size of one of the Neogene top predators was the subject of imaginative speculation and scientific investigation. Both the results... more

A new chondrichthyan fossil tooth was found from a float of the black shale of the Lower Jurassic Iwamuro Formation, Numata City (former Shirasawa Village), Gunma Prefecture, central Japan. The specimen (GMNH-PV-2406) is composed of a... more

A new chondrichthyan fossil tooth was found from a float of the black shale of the Lower Jurassic Iwamuro Formation, Numata City (former Shirasawa Village), Gunma Prefecture, central Japan. The specimen (GMNH-PV-2406) is composed of a platform-like flattened crown with rhomboidal outline. The crown has a complex ornamentation pattern. The ornamentation on the occlusal surface is finely reticulate with no occlusal crest. On the lateral surface, numerous striations are on the radical margin of each lateral side. These characteristics show that GMNH-PV-2406 is identified as a lateral tooth of Asteracanthus sp. This specimen marks the third record of the genus from Japan, and the first vertebrate fossil from the Iwamuro Formation and the Jurassic deposits of Gunma Prefecture respectively. The Asian fossil records of the genus
Asteracanthus, including GMNH-PV-2406, contribute to the understanding of distributional expansion timing, and the transition of Mesozoic shark fauna in
northwestern Panthalassa.

In this study, a diverse fauna of fossil elasmobranch teeth from the Early Miocene (Middle Burdigalian) is analysed. The fossil diversity strongly resembles extant deep-water shark and ray assemblages. The fossils were collected from the... more

In this study, a diverse fauna of fossil elasmobranch teeth from the Early Miocene (Middle Burdigalian) is analysed. The fossil diversity strongly resembles extant deep-water shark and ray assemblages. The fossils were collected from the Upper Marine Molasse of the lower Ottnangian in the Neuhofener Beds location, Mitterdorf, Germany. The collection site is a clay pit in between the Lower Bavarian villages Fürstenzell and Schmidham. The sample revealed 14 shark and four ray species. We present the first record of fossils assigned to taxa Nanocetorhinus tuberculatus, Deania and Apristurus from Germany. In addition, we describe a hitherto unknown genus and species of shark, Pseudoapristurus nonstriatus gen. et sp. nov., based on fossil teeth. The documented diversity is compared to both extant and fossil records of neoselachian deep-water diversities, and it is evident that this Miocene fauna is very similar in composition to indo-pacific deep-water assemblages. Zusammenfassung Aus der Oberen Meeresmolasse (Neuhofener Schichten, unteres Ottnangium) Niederbayerns (Tongrube zwischen Fürstenzell und Schmidham) wird eine artenreiche Tiefwasser-Elasmobranchierfauna beschrieben. Insgesamt werden 14 Hai-und vier Rochenarten nachgewiesen. Erstnachweise für Deutschland werden von Nanocetorhinus tuberculatus, Apristurus sp. und Deania sp. erbracht. Zusätz-lich wird eine bisher unbekannte Neoselachier Gattung und Art (Pseudoapristurus nonstriatus nov. gen. et sp.) anhand von Zahnfossilien beschrieben. Ein Vergleich der hier dokumentierten Diversität mit verschiedenen anderen rezenten und fossilen Neoselachier Vergesell-schaftungen zeigt, dass die vorliegende Fauna große Übereinstimmungen mit rezenter indo-pazifischer Tiefseediversität aufweist.

Elasmobranch remains are quite common in Miocene deposits and were the subject of numerous studies since the middle of the nineteenth century. Nevertheless, the taxonomic diversity of the Marine Molasse sharks, rays and skates is still... more

Elasmobranch remains are quite common in Miocene deposits and were the subject of numerous studies since the middle of the nineteenth century. Nevertheless, the taxonomic diversity of the Marine Molasse sharks, rays and skates is still largely unknown. Here, we describe 37 taxa from the lower Miocene of the Molasse Basin: 21 taxa could be identified at species level, whereas 15 taxa could only be assigned to genus and one taxon is left as order incertae sedis. The material was collected from deposits of the Auwiesholz Member of the Achen Formation (middle Burdigalian, middle Ottnangian age, ca. 17.8 Ma) exposed near Simssee, Upper Bavaria. This faunal assemblage is a mixture of shallow marine, near-coastal, pelagic and deep-water taxa. The fauna from Simssee displays different biogeographic dynamics at local and regional scales, possibly related to the intense climatic, oceanographic and tectonic events that occurred during the Eggenburgian-Ottnangian stages. The faunal relationships of the early Miocene chondrichthyan faunas from the Mediterranean Sea and Paratethys with others regions are established on the basis of qualitative (presence/absence) data. The beta diversity (Sørensen-Dice coefficient) of the Miocene Molasse elasmobranchs was used to characterize the taxonomic differentiation between localities and regions. According to our results, the fauna from Simssee shows close similarities with those from Switzerland, Austria, France and northern Germany. Faunal similarities and differences are mainly related to tectonic events and oceanographic variables (i.e. migration through seaway passages) or might represent collecting biases.

The isolated teeth of a new euselachian shark Artiodus prominens Ivanov and Duffin gen. et sp. nov. have been found in the Artinskian Stage (Early Permian) of Krasnoufimskie Klyuchiki quarry (Sverdlovsk Region, Middle Urals, Russia). The... more

The isolated teeth of a new euselachian shark Artiodus prominens Ivanov and Duffin gen. et sp. nov. have been found in the Artinskian Stage (Early Permian) of Krasnoufimskie Klyuchiki quarry (Sverdlovsk Region, Middle Urals, Russia). The teeth of Artiodus possess a multicuspid orthodont crown with from four to nine triangular cusps; prominent labial projection terminating in a large round tubercle; distinct ornamentation from straight or recurved cristae; oval or semilu-nar, elongate, considerably vascularized base; dense vascular network formed of transverse horizontal, ascending, short secondary and semicircular canals. The teeth of the new taxon otherwise most closely resemble the teeth of some prot-acrodontid and sphenacanthid euselachians possessing a protacrodont-type crown, but differ from the teeth of all other known euselachians in the unique structure of the labial projection. The studied teeth vary in crown and base morphology , and three tooth morphotypes can be distinguished in the collection reflecting a moderate degree of linear gradient monognathic heterodonty. The range of morphologies otherwise displayed by the collection of teeth shows the greatest similarity to that described for the dentitions of relatively high-crowned hybodontids from the Mesozoic. The internal structure of the teeth, including their vascularization system is reconstructed using microtomography. The highest chon-drichthyan taxonomic diversity is found in the Artinskian, especially from the localities of the Middle and South Urals.

The cheiracanthid acanthodiforms were widespread during the Middle Devonian, often being the most abundant acanthodians in northern European vertebrate macroand microfaunal assemblages. Three species of cheiracanthids, Cheiracanthus... more

The cheiracanthid acanthodiforms were widespread during the Middle Devonian,
often being the most abundant acanthodians in northern European vertebrate macroand
microfaunal assemblages. Three species of cheiracanthids, Cheiracanthus murchisoni,
C. grandispinus, and C. latus, have been known from the Middle Devonian
(Eifelian–Givetian) of northern Scotland since the nineteeth century. Here we review
the anatomy of these species and show that the main distinguishing features for the
three species are the scale ornamentation, general body shape, and relative robustness
of their scapulocoracoids and fin spines. They also show different stratigraphic
and geographic distributions in the Orcadian Basin. All three species appear at the
base of the Coccosteus cuspidatus + Pterichthyodes milleri placoderm biostratigraphic
zone; C. latus disappears towards the upper limit of this zone, C. murchisoni extends
into the base of the overlying Dickosteus threiplandi zone, and C. grandispinus
reaches up to the middle of this zone. Some cheiracanthid taxa based on isolated
scales from the Baltic countries, Belarus, and Russia are considered junior synonyms
of the Scottish species. The new data we provide should prove helpful in further elucidating
the taxonomic position of cheiracanthids.

"Present paper gives an updated summary of research history on the Chondrichthyes and Osteichthyes of the Early Triassic (Griesbachian, Dienerian, Smithian, Spathian) and primarily of the early Anisian. Early Triassic and Anisian marine... more

"Present paper gives an updated summary of research history on the Chondrichthyes and Osteichthyes of the Early Triassic (Griesbachian, Dienerian, Smithian, Spathian) and primarily of the early Anisian. Early Triassic and Anisian marine and freshwater ichthyofaunas are found on all continents except South America, and much more fish assemblages are known from the Northern than from the Southern Hemisphere. The Early Triassic and the Anisian are times of major importance for the phylogeny of the Chondrichthyes and Osteichthyes. After the end-Permian mass extinction the surviving groups of the cartilaginous and bony fishes recovered, and many new forms appeared in the Early Triassic. The neoselachians as well as close relatives of the teleosteans evolved, clades to which nearly all extant fishes belong. Present publication also provides a revised data base for the distribution of Early Triassic and early Anisian chondrichthyan and osteichthyan fishes in time and space on which future research on their paleobiodiversity shall be guided."

This first overview of the bony fish record from the Jurassic and Cretaceous continental deposits of Thailand reveals a significant diversity, with 16 taxa in four formations (the Khlong Min, Phu Kradung, Sao Khua and Khok Kruat Fms).... more

This first overview of the bony fish record from the Jurassic and Cretaceous continental deposits of Thailand reveals a significant diversity, with 16 taxa in four formations (the Khlong Min, Phu Kradung, Sao Khua and Khok Kruat Fms). Four of these taxa have already been diagnosed and described, and a couple of others are sufficiently well preserved to be diagnosed in the future. The other taxa are represented at present by fragmentary and isolated remains. The highest diversity is observed among ‘semionotids’, which occur in the four formations. Sinamiids are represented by at least three taxa that occur only in the Sao Khua and the Khok Kruat Formations. Pycnodont fishes are known by rare and isolated dentitions and teeth in the Khlong Min and Sao Khua Formations, and lungfishes referred to Ferganoceratodus occur in the Khlong Min and the Phu Kradung Formations. The assemblages provide few palaeogeographical indications at present, except for evidence of relationships with China and Central Asia. However, it is expected than once the phylogenetic relationships of these taxa are resolved, we will be able to reconstruct precise palaeogeographical scenarios.

part of on-going work on some of the earliest complete sharks with interesting dentitions, unexpected pectoral fin-spines and complex squamation, financed in part by the George Frederick Matthew Fellowship of the New Brunswick Museum... more

part of on-going work on some of the earliest complete sharks with interesting dentitions, unexpected pectoral fin-spines and complex squamation, financed in part by the George Frederick Matthew Fellowship of the New Brunswick Museum (2002, 2004, 2009) for work on Doliodus, Protodus and geology of the sites at Campbellton, Canada - contact co-author Dr Randall F. Miller to find out more about the Fellowship or visit NBM website.

The isolated teeth of a new euselachian shark Artiodus prominens Ivanov and Duffin gen. et sp. nov. have been found in the Artinskian Stage (Early Permian) of Krasnoufimskie Klyuchiki quarry (Sverdlovsk Region, Middle Urals, Russia). The... more

The isolated teeth of a new euselachian shark Artiodus prominens Ivanov and Duffin gen. et sp. nov. have been found in the Artinskian Stage (Early Permian) of Krasnoufimskie Klyuchiki quarry (Sverdlovsk Region, Middle Urals, Russia). The teeth of Artiodus possess a multicuspid orthodont crown with from four to nine triangular cusps; prominent labial projection terminating in a large round tubercle; distinct ornamentation from straight or recurved cristae; oval or semilu-nar, elongate, considerably vascularized base; dense vascular network formed of transverse horizontal, ascending, short secondary and semicircular canals. The teeth of the new taxon otherwise most closely resemble the teeth of some prot-acrodontid and sphenacanthid euselachians possessing a protacrodont-type crown, but differ from the teeth of all other known euselachians in the unique structure of the labial projection. The studied teeth vary in crown and base morphology , and three tooth morphotypes can be distingu...

From a newly discovered Early Cretaceous fossil site at the Sanlianhe Coal Mine in Tahe County, Heilongjiang Province, the most northern area in China, two freshwater fossil fish had been recovered. This paper reports their... more

From a newly discovered Early Cretaceous fossil site at the Sanlianhe Coal Mine in Tahe County, Heilongjiang Province, the most northern
area in China, two freshwater fossil fish had been recovered. This paper reports their classifications and implications regarding the
palaeobiogeography of the Jehol Biota. The fish assemblage consists of Yanosteus sp. (Acipenseriforms) and Sinamia sp. (Amiiformes). Both
are important members of the well known Jehol Biota, and their occurrence supports the correlation of the Yiliekede Formation at Sanlianhe
Coal Mine site with the Jiufotang Formation ofWest Liaoning. The remains of the Yanosteus sp. from this locality is the first known record of
the genus other than in the Yan-Liao area of China, and the specimens of Sinamia sp. is quite similar to what may be a new species of Sinamia
fromWest Liaoning. The new fossil site represents the most northern site that is undoubtedly part of the extent of the Jehol Biota as currently
understood. The northern Great Xing’an Range area is an important region that may link correlations between the Early Cretaceous
continental biotas of China, Mongolia and Russia.

This report serves to recount major contributions in the field of paleontology, throughout the lifetime of the South Dakota Academy of Science. The Proceedings of the South Dakota Academy of Science has provided an invaluable venue for... more

This report serves to recount major contributions in the field of paleontology, throughout the lifetime of the South Dakota Academy of Science. The Proceedings of the South Dakota Academy of Science has provided an invaluable venue for the descriptions and establishments of type specimens, poorly known bio-chronologic faunas, and research that covers many other aspects of paleontology. In several cases, the Proceedings provides the only recorded or citable information on a fossil site, taxonomic component, stratigraphic occurrence, or other information not provided elsewhere. We chronicle some of the most notable paleontological contributions through the South Dakota Academy of Science, and the major contributors who fully utilized this venue to make a wide variety of information available. There is great value in providing a venue for peer-reviewed research in a more academically relaxed atmosphere, which can be better utilized for citation. Some research may not be deemed significant enough for journals with more perceived prestige, and this hinders the release of potentially valuable information. Quality of research appears to be erroneously gauged by a journal's impact factor or notoriety rather than the content provided by the contributor. These accounts should not only serve to chronicle contributions, but encourage researchers to service this venue for continued academic productivity and further enrich the academic value of the organization.

The Green River Formation, Wyoming, contains such an abundance of well-preserved flora and fauna that this late early Eocene Lagerstätte is one of the best known from North America. Despite having being studied since the mid-nineteenth... more

The Green River Formation, Wyoming, contains such an abundance of well-preserved flora and fauna that this late early Eocene Lagerstätte is one of the best known from North America. Despite having being studied since the mid-nineteenth century, little is known about the taphonomic processes that resulted in a diverse suite of organisms, especially abundant fossil fish, being preserved in exquisite detail. Two distinct patterns of completeness and articulation recur among the fossil fish: complete and fully articulated, or extensive disarticulation of the anterior part of the fish only (‘half and half’ preservation). To decipher the processes involved in the preservation of Fossil Lake fish, specimens of the extant taxon Carassius auratus were decayed experimentally over a 6-month period. Various scenarios approximating conditions in the Eocene lake were replicated in the laboratory and each monitored to record the rate of degradation and how different starting conditions impacted on the taphonomy of the fish. Varying salinity or oxygen level did not induce any discernable differences in the pattern of decay; degradation occurred faster at higher temperatures. Unexpectedly, decay rates varied greatly between replicate samples. Soft tissues decomposed rapidly and extensively, and, even in the absence of any disturbance, the skeletal disarticulation that followed was repeatedly much greater than that exhibited by the vast majority of fossil fish from the Green River Formation. The results indicate clearly that decay in a quiet-water environment is, on its own, insufficient to explain the consistently high fidelity preservation of Green River fish: some additional factor is implicated. We propose that microbial mats at the sediment–water interface were key; fish carcasses became adhered to the sediment surface inhibiting floating, disarticulation and loss of bones, with ‘half and half’ specimens curving laterally and not fully adhering, thus only that part (typically the posterior) in contact with the substrate retained a high degree of skeletal fidelity.

†Erfoudichthys rosae gen. and sp. nov. is decribed on the basis of a single isolated head found in an unknown locality of the early Cenomanian Kem Kem beds, southeast of Morocco. The new species shows a combination of plesiomorphic and... more

†Erfoudichthys rosae gen. and sp. nov. is decribed on the basis of a single isolated head found in an unknown locality of the early Cenomanian Kem Kem beds, southeast of Morocco. The new species shows a combination of plesiomorphic and apomorphic characters among ostariophysans, such as a thin and elongated mesethmoid, a nasal formed by a cylindrical unit for the sensory canal extending laterally as a bony lamina, a large lacrimal, a small second infraorbital triangular in shape and wedged between the lacrimal and the third infraorbital, clusters of large conical teeth on the entopterygoids and basibranchial 2, a mandible with a ventral symphysal process and a deep coronoid process. A phylogenetic analysis of †E. rosae among gonorynchforms provides two very different patterns, with the new taxon located either as a stem Chanidae (= Chanoidei) or outside the Ostariophysi. This problematic phylogenetic resolution rests on the fragmentary condition of the available material and the lack of nonostariophysan teleosts for comparison, and prevents any analysis of the palaeobiogeographical signal that this taxon can provide

A brief memorial for Prof. Dr Alain Blieck 1949-2022

The paper discusses fish teeth from Middle Miocene (Badenian) marlstones and lithothamnion limestones from the Plesko quarry near Trbovlje, a raw-material base for the Lafarge cement plant. In Slovenia, finds of Miocene-age teeth of... more

The paper discusses fish teeth from Middle Miocene (Badenian) marlstones and lithothamnion limestones from the Plesko quarry near Trbovlje, a raw-material base for the Lafarge cement plant. In Slovenia, finds of Miocene-age teeth of cartilaginous and bony fishes are relatively common, but this is not the case in the Plesko quarry. Fish remains from the quarry include numerous scales of bony fishes and teeth belonging to three different genera including the species Cosmopolitodus hastalis, Diplodus jomnitanus and Pagrus cinctus.

The braincase of the Lower Cretaceous hybodont shark Tribodus limae is examined using high resolution CT scanning, and its internal and external morphology is described based on three-dimensional digital reconstructions. This study... more

The braincase of the Lower Cretaceous hybodont shark Tribodus limae is examined using high resolution CT scanning, and its internal and external morphology is described based on three-dimensional digital reconstructions. This study represents the first in-depth examination of a hybodont braincase using CT scanning and digital imaging technology. The braincase of an additional Lower Cretaceous hybodont, Egertonodus basanus, is also digitally reconstructed and compared to Tribodus. A reconstruction of cranial nerves and blood vessels in Tribodus is presented on the basis of preserved foramina. The braincase of Tribodus shares many features with those of Egertonodus and neoselachians, providing further support for the sister-group relationship between hybodonts and extant elasmobranchs. CT scans confirm that in both Tribodus and Egertonodus the glossopharyngeal and vagus canals converge and exit from a common foramen (also found in Chlamydoselachus). In both of the hybodonts examined, the trochlear nerve exits the braincase anterior to the optic nerve, a possible hybodont synapomorphy. Separate foramina for the two rami of the octaval nerve are present in both Tribodus and Egertonodus, and may represent an additional hybodont synapomorphy. Also, both taxa have three separate foramina for the trigeminal, facial, and anterodorsal lateral line nerves, apparently including an individual foramen for the superficial ophthalmic complex. However, the basicranial arterial system in Tribodus differs considerably from that of Egertonodus in that in the former the internal carotid arteries enter the braincase much farther posteriorly and through paired foramina rather than a single median foramen. The median ventral basicranial process in Tribodus is similar in structure and position to median ventral processes seen in some extant neoselachians (e.g., Etmopterus) and in embryonic Torpedo (although in the latter this structure disappears during development), and thus may have had a similar origin.

This is the first version of an “Host - Parasites List” of cartilaginous fishes (Chondrichtyes: Elasmobranchii, Holocephali). This first edition records more than 1.500 different species of parasites recovered from more than 400 species... more

This is the first version of an “Host - Parasites List” of cartilaginous fishes (Chondrichtyes: Elasmobranchii, Holocephali). This first edition records more than 1.500 different species of parasites recovered from more than 400 species of sharks, rays, skates and chimaeras. All information about the parasites are also available at http://shark-references.com/index.php/species/listValidRecent/A (weekly update).

The Late Triassic Rhaetian stage is perhaps best known in southwest Britain for the bone beds of the Westbury Formation, but there are other fossil-rich horizons within this and the underlying Blue Anchor Formation. Samples from a... more

The Late Triassic Rhaetian stage is perhaps best known in southwest Britain for the bone beds of the Westbury Formation, but there are other fossil-rich horizons within this and the underlying Blue Anchor Formation. Samples from a borehole drilled at the Filton West Chord, and collected from exposures near Bristol Parkway railway station, have yielded significant fossil material from both of these formations. The assemblage recovered from the Blue Anchor Formation is similar to those from the lower Westbury Formation, yielding roughly equal proportions of chondrichthyans and osteichthyans. Assemblages recovered from the Westbury Formation are typical of those from the upper Westbury Formation, in being dominated by osteichthyans. The borehole samples have produced the first recorded evidence of crinoids in the British Triassic, and the first evidence of coleoid cephalopods, in the form of grasping hooklets, from the Rhaetian, and indeed the first from the British Triassic.

The study of fossils has made considerable progress over the last years as a result of the use of new experimental techniques. This paper describes the chemical composition of a fossilized fish of the Cretaceous period, from a 100... more

The study of fossils has made considerable progress over the last years as a result of the use of new experimental techniques. This paper describes the chemical composition of a fossilized fish of the Cretaceous period, from a 100 million-year-old, material originated from the Araripe Basin (northeastern Brazil). The chemical composition of the fossilized fish was analyzed by means of X-ray powder diffraction and Fourier transform infrared spectroscopy (FT-IR). The spectroscopic study has proven that the main substances found in the fossilized fish are CaCO3 and Ca5(PO4)3(OH). A tentative mechanism to explain the fossilization process is also given.

Accumulating fossil records of deep-sea sharks are important for reconstruction of their paleoecology and evolution, because these fossils are generally rare everywhere in the world. This paper reports the newly discovered and diverse... more

SOUTH DAKOTA'S FOSSIL FISHES Fossil evidence from many locations in South Dakota and nearby areas documents the presence of many kinds of marine and freshwater fishes of the past. South Dakota's fossil fish date back to the Paleozoic Era,... more

SOUTH DAKOTA'S FOSSIL FISHES Fossil evidence from many locations in South Dakota and nearby areas documents the presence of many kinds of marine and freshwater fishes of the past. South Dakota's fossil fish date back to the Paleozoic Era, approximately 500 million years ago. The fossil evidence of prehistoric fishes may include entire skeletons, or various bones, teeth, ossified structures, scales, and otoliths. However, trace fossils of fish may also be recognizable in the fossil record, including resting traces and nesting traces. The literature lists hundreds of species and morphospecies of ancient fish or fishtypes which have been identified from fossil remains discovered in South Dakota and the surrounding region. Many of the fossil fish are archived and/or displayed either at the Museum of Geology and Paleontology at the South Dakota School of Mines and Technology in Rapid City, or the Black Hills Institute of Geological Research in Hill City. More specimens have been found in western than eastern South Dakota, but this is to be expected because layers of sediment are better exposed west of the Missouri River, particularly in and around the Black Hills and Badlands regions. Furthermore, glacial deposits left by continental ice sheets of the last one million years cover much of eastern South Dakota's bedrock. A summary of South Dakota's record of fossil fish, based on published literature and museum records is presented here. It is only a basic introduction that demonstrates the exceptional spectrum of resources resulting from 500,000,000 years of geologic time. No doubt this will be greatly increased and enhanced during future years as more evidence is found, identified, and archived for future generations. What should you do if you find or are given a fossil fish from a South Dakota locality? First, be aware that fossils of fish or their parts from South Dakota are fairly rare and they contain insight into an as yet poorly understood geologic past. Each fossil is a piece of an information puzzle, and potentially a very important one. If possible, identify where the fossil was found, how it was

An important character on several taxonomic levels for shark identification is the tooth morphology. Sharks show a variety of highly specialized dentitions reflecting adaptations to their feeding habits. Intraspecific variation of tooth... more

An important character on several taxonomic levels for shark identification is the tooth morphology. Sharks show a variety of highly specialized dentitions reflecting adaptations to their feeding habits. Intraspecific variation of tooth morphology such as sexual or ontogenetic dimorphism is poorly known in many species, even though tooth morphology plays a decisive role in the characterization of the fossil record of sharks, which comprises mostly fossil teeth. Here we analyzed the dentition of 40 jaws of the Velvet Belly Lantern Shark Etmopterus spinax and identified ontogenetic and sexual dimorphic characters such as total number of teeth, number of upper teeth, cusplet numbers in upper jaw teeth and width of lower jaw teeth. Dimorphic characters may reduce intraspecific competition for food, as E. spinax segregates by sex and size and may allow for identifying the male sex. The lower jaw tooth height, a sexually non-dimorphic character, was used to recalculate the total length of specimens, which represents the first such approach for a squaliform shark. Results derived from the extant E. spinax are subsequently applied to fossil Etmopterus sp. teeth (Miocene) to gain individual information such as sex or size, but also characterize the extinct population from the excavation site by a size distribution profile in comparison to data from extant populations. This approach indicates the presence of multiple ontogenetic stages in the extinct population.