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First report of Cylindracanthus (Osteichthyes) from the Eocene of India
Published online: 3/25/24
Keywords:
Cylindracanthus; Eocene; histology; rostrum; Umarsar mine.
https://doi.org/10.18563/pv.47.1.e2
Abstract
Fossils of the endangered sturgeons and peddlefishes are widely distributed. We here report for the first time the presence of one of the extinct osteichthyes genus Cylindracanthus (Liedy 1856a) from the Early Eocene lignite-bearing successions of the Kutch Basin, India. The present well preserved rostrum is characterised by numerous wedge-shaped components encircling the central canal that runs along its length, paired at the base and each wedge contributing to the formation of a ridge. The rostrum lacks teeth. The present find extends the palaeobiogeographical distribution of Cylindracanthus considerably and supports its Eocene age as dental remnants preserved in Cylindracanthus sp. shows a decrease in remanent dentition and tooth bases from the Cretaceous to the Eocene. Cylindracanthus is an useful palaeoenvironmental indicator as it has been found associated typically with deposits of nearshore marine environments.
PV article infos
Published in 47-1 (2024)
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Pterosaurs (Pterosauria) from the Cerro del Pueblo Formation (Late Campanian) of Coahuila, Mexico
Published online: 11/21/25
Keywords:
Azhdarchoidea; Coahuila; Mexico; Pterodactyloidea; Pterosauria
https://doi.org/10.18563/pv.48.2.e1
Abstract
The Late Campanian Cerro del Pueblo Formation, located in southeastern Coahuila, Mexico, has produced a diverse array of vertebrate fossils. However, pterosaur remains from this unit are notably scarce. In this study, we describe new pterosaur material from the formation. The specimens include a fragmentary vertebra identified as belonging to an indeterminate, but derived pterodactyloid, along with the distal condyle of a left metacarpal, referable to an azhdarchoid pterosaur, and a left manus print. While these specimens provide additional evidence of pterosaur presence in the region during the Late Cretaceous, their fragmentary nature limits precise taxonomic and ichnotaxonomic identification. Nevertheless, they highlight the potential for future discoveries that could refine our understanding of the diversity and distribution of pterosaurs in Mexico.
PV article infos
Article state: in_press
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Revision of the historical collections of Pliocene-Pleistocene large mammals from Le Riège and Saint-Palais localities, near Pézenas (Southern France)
Published online: 6/23/25
Keywords:
Hérault; Mammalia; Montpellier; Neogene; Quaternary
https://doi.org/10.18563/pv.48.1.e2
Abstract
Numerous “Quaternary” large-mammal fossils have been collected since the 1830s along the Le Riège stream, near Pézenas (Southern France). More than 120 specimens are stored in the collections of the Université de Montpellier (UM) under the name “Le Riège”. A major operation aiming at relocating the palaeontological collections of the University has made it possible to group together all the specimens of interest and launch their systematic revision for the first time. The fossils belong to the Reboul (1839; 51 samples) and de Christol (1865; 18 samples) Collections and 17 samples compose the Crochet & Ivorra Collection (1998). The remaining 38 samples have no mention about the exact time and location of their finding. We provide a critical inventory with literal transcription of inscriptions on specimens and historical labels. This revision confirms the presence of two distinct faunal assemblages under the name of “Le Riège”: Saint-Palais (Early Pliocene, MN14–15) and Le Riège sensu stricto (late Early Pleistocene, most likely MNQ19). The former assemblage, with coastal affinities, is composed of the ruminants Alephis sp. and Procapreolus cf. pyrenaicus, the rhinocerotid Pliorhinus megarhinus, the gomphotheriid Anancus arvernensis and marine mammals, all emblematic taxa for the Early Pliocene of Montpellier and Perpignan. The latter assemblage documents a late Early Pleistocene fluvio-volcanic sequence, yielding the bovid Bison (Eobison) spp., the cervid Eucladoceros cf. giulii, the hippopotamid Hippopotamus antiquus, the rhinocerotid Stephanorhinus etruscus, the equid Equus cf. altidens, and the elephantid Mammuthus cf. meridionalis, plus a few specimens of uncertain taxonomic affinities. This revision underscores the interest of revisiting historical collections and further provides a starting point for future research.
PV article infos
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Preliminary report on the fishes (Chondrichthyes & Teleostei) from the lower Oligocene (Rupelian) Red Bluff Clay at site AMo-9, Monroe County, Alabama, USA
Published online: 6/26/24
Keywords:
Batomorphii; Elasmobranchii; Galeomorphi; Gulf Coastal Plain; Vicksburg Group
https://doi.org/10.18563/pv.47.2.e2
Abstract
Herein we describe a small but relatively diverse assemblage of fossil fishes derived from the lower Oligocene (Rupelian) Red Bluff Clay at site AMo-9 in Monroe County, Alabama, USA. Identified amongst the remains are 15 unequivocal taxa representing 11 families within five orders, and one additional taxon represents an unknown order and family. Taxa identified include Eostegostoma sp., Otodus (Carcharocles) sp., Mitsukurinidae/Carchariidae indet., Macrorhizodus praecursor, Galeorhinus sp., Negaprion gilmorei, Physogaleus sp., “Sphyrna” sp., Galeocerdo sp., cf. “Aetobatus” sp., Sphyraena sp., Xiphiorhynchus kimblalocki, Xiphiorhynchus sp., Cylindracanthus ornatus, and C. rectus. Several additional fossils could not be identified beyond Lamniformes, Carcharhiniformes, and Teleostei, but they likely belong to one of the identified taxa within this paleofauna. All of the fishes previously reported from the Red Bluff Clay within the entirety of the Gulf Coastal Plain of the USA are otolith-based, and each of the 15 unequivocal taxa reported herein are important new records for this lithostratigraphic unit. In particular, the Eostegostoma sp. and Xiphiorhynchus spp. specimens represent the first occurrences of these taxa in Alabama. The specimens of C. ornatus, Eostegostoma sp., and X. kimblalocki are stratigraphic and temporal range extensions from the middle and late Eocene into the Rupelian Stage of the Oligocene. Other described taxa may represent transitional forms between those described from the late Eocene and late Oligocene within the region. This study provides a tantalizing preliminary view into faunal transitions that occurred amongst marine fishes across the Eocene/Oligocene boundary within the Gulf Coastal Plain of the USA.
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Lissamphibians from Dams (Quercy, SW France): Taxonomic identification and evolution across the Eocene-Oligocene transition
Published online: 6/25/25
Keywords:
Eocene-Oligocene; Grande Coupure; Lissamphibia; Quercy Phosphorites
https://doi.org/10.18563/pv.48.1.e3
Abstract
The locality of Dams (Quercy, southwestern France) has yielded two fossil assemblages, one from the late Eocene and another from the early Oligocene, making it one of the few localities with infillings across the Eocene-Oligocene transition. At least 24 taxa (13 mammals, 11 snakes) have been identified in this locality. Study of the lissamphibian remains from Dams yields an Eocene and an Oligocene assemblage, with a total of eight taxa. The Eocene assemblage includes two unnamed salamandrine species, one unnamed pelobatid species and one pyxicephalid species (Thaumastosaurus). The Oligocene assemblage includes two unnamed pleurodeline species, one salamandrine species (Salamandra sansaniensis) and an unnamed pelobatid species. Among the eight taxa from Dams, one Eocene salamandrine and one Oligocene pleurodeline are identified for the first time in the Quercy. A review of the lissamphibians from the Quercy area identifies eleven taxa for the Late Eocene (MP19) and eight taxa for Early Oligocene (MP22), with a major turnover at the Eocene-Oligocene transition. This turnover occurs in a time of major climatic changes, with a significant decrease in temperature and precipitation and concurrent increase in seasonality in Europe, likely affecting specialized taxa.
PV article infos
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Enigmatic rodents from Lavergne, a late middle Eocene (MP 16) fissure-filling of the Quercy Phosphorites (Southwest France)
Published online: 4/8/24
Keywords:
diversity; late Bartonian; Rodentia; taxonomy; Theridomyidae
https://doi.org/10.18563/pv.47.2.e1
Abstract
Two somewhat “odd” taxa of theridomyid rodents, one formerly known (Bernardia marandati Vianey-Liaud, 1991) and the other new (Idicia vidalenci gen. et sp. nov.) are discussed from a taxonomical and taphonomical perspectives. These two rodents were found at Lavergne, a late middle Eocene (MP16) “phosphatière” from the Quercy (Southwest France). The genus Bernardia, being preoccupied by a scale insect (Bernardia Ashmead, 1881), is here renamed Burgia. We benefit from this nomenclatural change to describe additional new dental specimens of this patriotheridomyine species, including a previously undescribed locus (P4). The other theridomyid from Lavergne, Idicia vidalenci gen. et sp. nov., so far documented by a mandible preserving two teeth (m2-m3) is a new taxon of peculiar occlusal morphology, and whose subfamilial affinities remain unknown. These two peculiar theridomyids recorded at Lavergne are found nowhere else, whether in coeval localities in Quercy or elsewhere in Western Europe. We discuss the possible causes of their unique presence at Lavergne.
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Book of Abstracts of the XXII Annual Meeting of the European Association of Vertebrate Palaeontologists, 30 June–5 July 2025, Kraków, Poland
Published online: 6/20/25
Keywords:
Abstracts; EAVP
https://doi.org/10.18563/pv.eavp2025
Abstract
Book of Abstracts of the XXII Annual Meeting of the European Association of Vertebrate Palaeontologists, 30 June–5 July 2025, Kraków, Poland.
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A partial skeleton of Metaxytherium medium from the middle Miocene of La Morfassière quarry (Indre-et-Loire, France)
Published online: 1/16/25
Keywords:
Faluns; France; Metaxytherium; Miocene; Sirenia
https://doi.org/10.18563/pv.48.1.e1
Abstract
Sirenians are among the common marine fossil remains found in the Faluns deposits of western France. We describe new material of a Dugongidae sirenian from the middle Miocene Savignean facies of La Morfassière quarry (Indre-et-Loire, northwestern France) that includes a well preserved and almost complete skull associated with its mandible, several vertebrae and ribs. The cranial remains exhibit features that allow to attribute them to Metaxytherium medium, a species recorded from the middle and early late Miocene of European and Mediterranean coasts. The discovery of an associated skull and mandible of this species is unusual in this area and deserves to be reported, mostly because its preservation contributes to a better knowledge of the variable structure of its skull and teeth anatomy. For the first time the body size and weight of M. medium can be assessed through regression equations based on skull measurements. The particularly good condition of the material can be explained by the calm and deep marine environment in which it was deposited.
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A late Eocene palaeoamasiine embrithopod (Mammalia, Afrotheria) from the Adriatic realm (Island of Rab, Croatia)
Published online: 12/14/23
Keywords:
Balkanatolia; Grande Coupure; Great Adria; Paleobiogeography; Systematics
https://doi.org/10.18563/pv.47.1.e1
Abstract
A cheek tooth recently unearthed in the Lopar Sandstone unit, of late Eocene age, in the northern part of Rab Island, Croatia, is one of the very few Eocene mammalian remains found in the Adriatic area. Thorough comparison of this tooth with those of Old-World Palaeogene mammalian orders suggests that it is a M3 belonging to an embrithopod afrothere. The specimen is referred to as Palaeoamasia sp. This genus was formerly known only in Eocene deposits of Anatolia but with close relatives in Romania among Palaeoamasiinae. The geographical distribution of this subfamily perfectly matches the recently-named Balkanatolian landmass, which experienced in-situ evolution of endemic mammals prior to the Grande Coupure event that occurred around the Eocene–Oligocene transition. This last event is characterised by massive Asian immigration in Western Europe and the supposed extinction of many endemic Central and Western European mammals, including Palaeoamasiinae.
PV article infos
Published in 47-1 (2024)
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Abstract book of the 18th Conference of the European Association of Vertebrate Palaeontologists (EAVP), 5-9 July 2021, Benevento, Italy
Published online: 7/12/21
Keywords:
2021; Abstracts; Benevento; EAVP
https://doi.org/10.18563/pv.eavp2021
Abstract
Welcome to the 18th conference of the EAVP, the first online meeting of our association. The pandemic emergency made it impossible to organize the in-person meeting in Benevento as we all had hoped. However, we couldn’t miss another EAVP meeting. Therefore, this year we are meeting online, trying to make the experience the closest to the in-person meeting possible, in order to offer the delegates the opportunity to share knowledge, build new networks and reinforce the old ones. We have received 137 communications, with more than 150 delegates from 24 countries. All the abstracts have passed a peer review process and are part of this special volume of Palaeovertebrata, the official journal of the EAVP. This year we are also offering a variety of workshops, roundtables and symposia on different topics. These include the annual “Pride EAVP: An LGBTQ+ Roundtable” and “Women in Palaeontology Roundtable Discussion”, together with the workshops on “Gendered Perspective in Palaeontological Research: from Definition to Action”, “International Palaeontology Education: Virtual Teaching and Real-World Learning”, “Stepping out of Academia: Why, When and How?”, “Introduction to Hypothesis Testing in Statistics”, “The Early-Middle Pleistocene Transition: Marked Mammal Turnover and Ecosystem Dynamic” (included in the early event for the XXI INQUA Congress in Rome 2023, “A Mediterranean Perspective on Quaternary Sciences”). To conclude, we are hosting two symposia on “Palaeoart: Diversity on and behind the Canvas” and “3D fossils, Robotic and Experimental Palaeontology”. We wish you all a happy and productive meeting. And see you in Benevento next year!
PV article infos
Published in Special Volume 1-2021 (2021)
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The geologically youngest remains of an ornithocheirid pterosaur from the late Cenomanian (Late Cretaceous) of northeastern Mexico with implications on the paleogeography and extinction of Late Cretaceous ornithocheirids
Published online: 7/21/20
Keywords:
Coahuila; Late Cenomanian; north-eastern Mexico; Ornithocheiridae; Pterosauria
https://doi.org/10.18563/pv.43.1.e4
Abstract
Ornithocheirid pterosaurs were the largest of the toothed pterodactyloids and had a worldwide distribution, although their fossil record is fragmentary, with the exception of the north-eastern Brazilian Crato and Santana Formations (Aptian, ?Albian, Early Cretaceous). With Istiodactylidae, they were also the only toothed pterosaurs that survived into the Cenomanian (Late Cretaceous), becoming extinct at the end of this period. Here we report on an ornithocheirid metacapus from the Late Cenomanian laminated limestone of north-eastern Mexico discovered about 120 km north-west of Ciudad Acuña, northern Coahuila at the south banks of Rio Bravo. The specimen comprises a fragmentary distal syncarpal, a crushed but complete metacarpal IV, two fragmentary preaxial metacarpals and a possible fragmentary terminal left wing finger phalanx. It represents the geologically youngest known ornithocheirid worldwide. We suggest that ornithocheirid pterosaurs may have become extinct because of massive sea level fluctuations during the mid to late Cretaceous that may have obliterated their breeding sites on coastal plains and low lying islands.
PV article infos
Published in Vol 43-1 (2020)
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Le genre Leptolophus (Perissodactyla, Mammalia): morphologie et histologie dentaires, anatomie cranienne, implications fonctionnelles.
Published online: 9/15/98
Keywords:
dental histology; Eocene; functional anatomy; Palaeotheriidae; skull anatomy; Southern France; Systematics
Abstract
A strong lophodonty, an extreme heterodonty, some hypsodonty and regular overlayings of coronal cement are prominent features of the genus Leptolophus (Palaeotheriinae = Palaeotheriidae s.s.). The histological pattern of the teeth unusually joins type II enamel prisms, characteristic of advanced ungulates, together with archaic features, such as an almost complete lack of Hunter-Schreger zonation and a weak expanse of peritubular dentine. The skull is narrow and slender, with an elongated ante-orbital facial region, a moderately notched nasal aperture, a rather elongated post-canine diastem, parallel zygornatic arches and a fairly dorsally located squamoso-mandibular joint.The functional analysis brings to light "ectolophodont" masticatory cycles with two phases, in which maximum power was applied, contrary to equíds, on hindmost teeth; likewise, skull accomodations to increasing height of the teeth are quite different. This study leads to the assumption that Leptolophus may have been light mammals, living in rather open surroundings, browsing on herbaceous plants or leaves cropped close to the ground. Moreover, it appears that it could have been some inadequacy of dental structures to the dietary, which leaded to quick wear of the teeth and to many enamel notches, but had been somewhat balanced by the early increase of hypsodonty, not induced in such a case by a biotop deterioration (as it will happen at the end of the Eocene). This ínadaptation might account for the short duration of the genus Leptolophus, whose the 3 species, L. stehlini, L. nouletí and L. magnus n. sp. are indeed confined in the level MP 16. Its geographical spreading (as far as known, South of western Europe) and the morphological pattern of its dentition suggest that this genus would have been related to early upper Eocene endemic spanish forms.
PV article infos
Published in Vol. 27, Fasc. 1-2 (1998)
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A new species of bat (Chiroptera: Vespertilionidae) from the early Oligocene global cooling period, Brule Formation, North Dakota, USA
Published online: 12/9/19
Keywords:
Eocene-Oligocene global cooling; Mammalia; Oligocene; Plecotini; Quinetia
https://doi.org/10.18563/pv.42.2.e2
Abstract
We report the first confirmed fossil bats from North Dakota, including a new species referable to the Vespertilionidae represented by a maxilla with P4-M3 from the Brule Formation, Fitterer Ranch local fauna, early Oligocene, Whitneyan North American Land Mammal Age. Unassociated postcranial fragments of the humerus and femur also represent a vespertilionoid, but appear to reflect a different, unidentified species. The new taxon, Quinetia frigidaria sp. nov., is referred to the genus Quinetia, previously known only from approximately contemporaneous deposits in Europe. The new species is larger than Quinetia misonnei from the early Oligocene of Belgium. It is similar in some morphological characters to Chadronycteris rabenae (Chiroptera incertae sedis) of the late Eocene (Chadronian) of northwestern Nebraska and to Stehlinia species (?Palaeochiropterygidae) from the Eocene and Oligocene of Europe, but differs from each in morphological details of the dentition and maxilla. An unassociated talonid of a lower molar from Fitterer Ranch shows myotodont morphology, unlike the nyctalodont lower molars in Q. misonnei, and thus represents a second chiropteran taxon in the fauna. Quinetia frigidaria is a member of a Paleogene radiation of bats near the low point of the Eocene-early Oligocene decline in global temperatures, increased seasonal aridity, and loss of tropical floras from mid-latitude North America.
PV article infos
Published in Vol 42-2 (2019)
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Fallen in a dead ear: intralabyrinthine preservation of stapes in fossil artiodactyls
Published online: 3/9/16
Keywords:
allometry; bony labyrinth; inner ear; middle ear ossicles
https://doi.org/10.18563/pv.40.1.e3
Abstract
The stapes is the last of the middle ear ossicle chain and the smallest bone of the mammalian skeleton. Because it rests on the membrane of the fenestra vestibuli during life, the stapes may often fall within the bony labyrinth cavity when soft structures decay after death. In this work, we highlight the unexpected role that the bony labyrinth plays in the preservation of the stapes. Systematic investigation of the bony labyrinth of 50 petrosal bones of extinct and extant artiodactyls led to the discovery of eight cases of “intralabyrinthine” stapes. Three dimensional reconstructions of these stapes allow documenting stapes morphology of four extinct artiodactyl taxa: Microstonyx erymanthius (Suidae), Elomeryx borbonicus (Hippopotamoidea), ?Helohyus plicodon (Helohyidae), and an undetermined Cainotheriidae; and four extant ones Choeropsis and Hippopotamus (Hippopotamidae), and Tayassu and Phacochoerus (Suoidea). ?Helohyus plicodon from the Middle Eocene documents the oldest stapes known for the order Artiodactyla. Morphological study and metric analyses of our sample of artiodactylan stapes show that stapes are likely to carry relevant phylogenetic characters/signal within artiodactyls, and a potential Euungulata signature.
PV article infos
Published in Vol.40-1 (2016)
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An evening bat (Chiroptera: Vespertilionidae) from the late Early Eocene of France, with comments on the antiquity of modern bats
Published online: 8/1/16
Keywords:
evolution; palaeobiogeography; Prémontré; Western Europe; Ypresian
https://doi.org/10.18563/pv.40.2.e2
Abstract
Bats are among the most numerous and widespread mammals today, but their fossil record is comparatively meagre and their early evolution poorly understood. Here we describe a new fossil bat from dental remains recovered from late Early Eocene sediments at Prémontré, northern France. This 50 million-year-old bat exhibits a mosaic of plesiomorphic and apomorphic dental features, including the presence of three lower premolars, a single-rooted p3, short p4 with metaconid, myotodont lower molars and a tall coronoid process of the dentary. This combination of features suggests it is an early member of Vespertilionidae, today’s most speciose and geographically widespread bat family. The Prémontré bat has bearing on hypotheses about the origins of vesper or evening bats (Family Vespertilionidae), as well as crown-group chiropterans.
PV article infos
Published in Vol.40-2 (2016)
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First record of the family Protocetidae in the Lutetian of Senegal (West Africa)
Published online: 12/5/14
Keywords:
innominate; Lutetian; Protocetid; Senegal
https://doi.org/10.18563/pv.38.2.e2
Abstract
The earliest cetaceans are found in the early Eocene of Indo-Pakistan. By the late middle to late Eocene, the group colonized most oceans of the planet. This late Eocene worldwide distribution clearly indicates that their dispersal took place during the middle Eocene (Lutetian). We report here the first discovery of a protocetid fossil from middle Eocene deposits of Senegal (West Africa). The Lutetian cetacean specimen from Senegal is a partial left innominate. Its overall form and proportions, particularly the well-formed lunate surface with a deep and narrow acetabular notch, and the complete absence of pachyostosis and osteosclerosis, mark it as a probable middle Eocene protocetid cetacean. Its size corresponds to the newly described Togocetus traversei from the Lutetian deposits of Togo. However, no innominate is known for the Togolese protocetid, which precludes any direct comparison between the two West African sites. The Senegalese innominate documents a new early occurrence of this marine group in West Africa and supports an early dispersal of these aquatic mammals by the middle Eocene.
PV article infos
Published in Vol.38-2 (2014)
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First Neogene Otonycteris (Chiroptera: Vespertilionidae) from Ukraine: its biostratigraphic and paleogeographic significance.
Published online: 3/19/15
Keywords:
bats; East Europe; Gritsev; Late Miocene; Mammalia
https://doi.org/10.18563/pv.39.1.e2
Abstract
A new species, Otonycteris rummeli nov. sp., is described from the Late Miocene site Gritsev (MN 9) in the Ukraine. Otonycteris rummeli nov. sp. differs from those of most vespertilionids, except recent Otonycteris, Antrozous and Early Miocene Karstala silva, in having a well-developed entocingulid at the foot of the trigonid valley in the lower molars. The morphological resemblance of Otonycteris, Antrozous and Karstala is apparently a case of convergence in the evolution of the Old and New Worlds bat faunas. From at least the Middle Miocene the range of Otonycteris distribution spread to the whole of Central Europe and such a situation continued during the whole Late Miocene. This indicates a more arid climate in Europe during the Upper Miocene compared to the Quaternary. The reduction of the distribution range of Otonycteris and its extinction in most of the territory of Europe could have been caused by the global climatic cooling and increasing glacial cycle amplitude during the onset of the Quaternary.
PV article infos
Published in Vol.39-1 (2015)
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Révision systématique des Anchilophini (Palaeotheriidae, Perissodactyla, Mammalia).
Published online: 10/15/12
Keywords:
Anchilophus; Eocene; new genus; new species; Palaeotheriidae; Paranchilophus; Perissodactyla; Systematics
https://doi.org/10.18563/pv.37.1-3.1-165
Abstract
The knowledge of the Anchilophini has been lately renewed by the discovery of a rather large amount of new material still largely unpublished. This new material offers the opportunity of a systematic revision of this tribe gathering those of European Eocene Equoidea which bear no mesostyle on upper check teeth and display a heavy trend to the molarization of premolars.
A cladistic analysis has made out two genera, Anchilophus (Paranchilophus included as a subgenus), characterized by a marked lophodonty and the transverse narrowness of the cheek teeth, a rather high hypsodonty, the frequent occurrence of "crochets" and "anticrochets" on the superior ones, and a rather weak molarization of the premolars, opposite to Metanchilophus n. gen. whose cheek teeth are more transversally elongated, less high, less lophodont, with cusps better distinct, enamel thicker and premolars more molarized on the whole.
Three species of Anchilophus are recognized, A. desmaresti, type species of the genus, A. (Paranchilophus) remyi and A. (Paranchilophus) jeanteli n. sp.
The genus Metanchilophus is more diversified with the species dumasi, radegondensis, gaudini (whose a new sub-species M. g. fontensis is defined), depereli, castrensis n. sp. and chaubeti n. sp.
The skull anatomy has been moreover described with several taxa; it brings to light (for all that one can generalize) that Anchilophini were light animals with a slender and elongated snout, a thin zygomatic arch, a rather developed encephalon with an advanced gyrencephaly.
The structure of the nasal opening together with the occurrence of epitympanic sinuses and the molarizing process of the premolars corroborate the attribution of this tribe to the family PalaeotheIiidae.
PV article infos
Published in Vol. 37, Fasc. 1-3 (2012)
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Eocene Teleostean Otoliths, Including a New Taxon, from the Clinchfield Formation (Bartonian) in Georgia, USA, with Biostratigraphic, Biogeographic,
and Paleoecologic Implications
Published online: 1/3/22
Keywords:
climate; Congridae; Ophidiidae; Sciaenidae; tectonics
https://doi.org/10.18563/pv.45.1.e1
Abstract
Investigations of the Clinchfield Formation (middle Eocene, upper Bartonian) exposed at the Hardie Mine (Wilkinson County, Georgia, USA), produced 4,768 actinopterygian otoliths representing 14 taxa and increased the number of bony fishes threefold from the site. The somewhat limited richness was characterized by bonefishes, mud eels, conger eels, sea catfishes, cusk-eels, snooks, grunts, drums and croakers, and porgies. The assemblage had a relatively even distribution with Ophidiidae, Congridae, and Sciaenidae most common. Included in the otolith taxa was a new sciaenid genus and species, Eosciaena ebersolei, with unknown relationships to other Sciaenidae. The Clinchfield otoliths were compared to other middle and late Eocene in age otolith assemblages in Alabama, Mississippi, and Louisiana utilizing percentage similarity measurements. Analysis indicated that the Clinchfield otoliths were not greatly similar or greatly unlike the Moodys Branch and Yazoo Clay otolith assemblages. However, the Clinchfield showed little relationship to the slightly older Lisbon Formation in adjacent Alabama and is postulated to be related to global climatic and plate tectonic events. Biostratigraphically, the Clinchfield otolith taxa are essentially the same as the other formations except for the Lisbon, which has at least ten unique species. Abundances of Clinchfield otolith taxa indicate a possible sub-bioprovince in the eastern Gulf Coastal Plain. The Clinchfield otoliths indicate a tropical to perhaps subtropical, soft substrate, mainly normal marine to slightly reduced salinities, inner shelf (0–20 m) paleoenvironment with indications of proximal continental coastlines. This investigation represents an initial step in addressing the immensely understudied Paleogene otolith assemblages in Georgia.
PV article infos
Published in 45-1 (2022)
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A new study of the anthracotheres (Mammalia, Artiodactyla) from pondaung formation, Myanmar: systematics implications
Published online: 12/16/08
Keywords:
Anthracohyus; Anthracokeryx; Anthracotherium; Pondaung Formation; sexual dimorphism; Siamotherium; South East Asia; taxonomy
https://doi.org/10.18563/pv.36.1-4.89-157
Abstract
Anthracotheres from the Pondaung Formation, Myanmar, are considered as one of the most primitive artiodactyl groups and they represent the oldest known record in the world. Thus, the understanding of this group has numerous implications for evolutionary biology and biochronological correlations. However, the systematlcs of these mammals has been interpreted in different ways, and the main debate focuses on the number of taxa represented in the Pondaung Formation. The revised taxonomy proposed here is mainly based on the relative development of the upper molar W-shaped ectoloph, system of crests and stylar cusps, and on body size. On the basis of these characters, they are classified into four genera including six different species. Two well-known genera, Anthracotherium and Anthracokeryx, are validated and more precisely diagnosed. Anthracokeryx possesses a better developed W-shaped ectoloph, system of crests and stylar cusps than Anthracotherium, which displays notable differences with the more derived representatives of this genus. Both of these Pondaung genera show evidence for sexual dimorphism. However, the incompleteness of fossil material fueled a debate concerning the status of two additional Pondaung anthracotheres, Siamotherium and Anthracohyus. The latter genus is of uncertain affinities, but it has been considered as a hippopotamid ancestor. Despite new material attributed to these two forms, additional discoveries are still required to establish their taxonomic status. The hypothesis that Southeast Asia was the centre of origin of Anthracotheriidae is supported by the retention of numerous primitive dental characters in these taxa and by the antiquity of the Pondaung Formation, to which an age of 37 My is now generally accepted.
PV article infos
Published in Vol. 36, Fasc. 1-4 (2008)
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