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First record of dinosaur eggshells and teeth from the north-west african Maastrichtian (Morocco).
Published online: 15/12/2003
Keywords:
Africa; amniotic eggshells; Maastrichtian; Morocco; theropod teeth
https://doi.org/10.18563/pv.32.2-4.59-69
Abstract
We report the discovery of amniotic eggshells and theropod teeth from the Late Cretaccous period in Morocco.The megaloolithid family represents the only known dinosaur egg remains in the north part of Africa and attests indirectly to the occurrence of sauropod dinosaurs (titanosaurids) in the Maastrichtian of Africa.
PV article infos
Published in Vol. 32, Fasc. 2-4 (2003)
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Mammals and stratigraphy of the continental mammal-bearing Quarternary of South America
Published online: 16/12/1984
Keywords:
Geochronology; Mammalia; Quaternary; South America; Stratigraphy
https://doi.org/10.18563/pv.14.ext
Abstract
Previous chronological arrangements of South American Quaternary land mammal faunas are appraised on the basis of current geological and paleontological data. Three South American late Pliocene-Pleistocene land mammal ages are conventionally recognized, from oldest to youngest, the Uquian, Ensenadan, and Lujanian ; all are defined on Argentine faunas.
The Uquian is based fundamentally and historically on the fauna from the Uquía Formation in Jujuy Province, northwestern Argentina. Important known formations in Argentina yielding Uquian Age faunas include the sub-surface Puelche Formation (or Puelchense) near the city of Buenos Aires, and the Barranca de Los Lobos and Vorohué Formations between Mar del Plata and Miramar, Buenos Aires Province. A tentative subdivision is propos-ed for the Uquian into three subages based on knowledge of the Mar del Plata-Miramar sequence, from oldest to youngest, the Barrancalobian, Vorohuean, and Sanandresian. In Argentina the Uquian is presently marked by the first known record of Scelidodon, Hydrochoeropsis, Ctenomys, Canidae, Ursidae, Gomphotheriidae, Equidae, Tapiridae, Camelidae, Cervidae, and the last known record of Thylatheridium, Thylophorops, Dankomys, Eumysops, Pithanotomys, Eucoelophorus, Hegetotheriidae, Sparassocynidae, and Microtragulidae.
The Ensenadan Age is based on the fauna from the Ensenada Formation near the city of Ensenada, Buenos Aires Province. In Argentina the Ensenadan is marked by the first known record of Lomaphorus, Neothoracophorus, Plaxhaplous, Cavia, Lyncodon, Lutra, Galera, Smilodon, Dicotyles, Lama, Vicugna, the last known record of Orthomyctera, and the only known record of Brachynasua.
Typícal beds of late Lujanian Age in Argentina consist of fluvial deposits occupying stream channels, and shallow basins, often incised into beds of early Lujanian (i.e. Bonaerian of early workers) and Ensenadan Age. The Lujanian Age is based on a fauna from beds along the Rio Luján, about 65 km west of the city of Buenos Aires, Buenos Aires Province. The Lujanian in Argentina is marked by the first record of Equus, Chlamyphorus, and Holochilus, and the last record of Megatherioidea, Glyptodontoidea, Arctodus (=Arctotherium), Smilodon, Litopterna, Notoungulata, Proboscidea, Equidae, Morenelaphus, and Palaeolama.
These land mammal ages are often difficult to recognize in other South American countries. The compositions of South American Pleistocene faunas vary with the environment. Some taxa were widely distributed in fossil deposits throughout the continent, but their occurrences need not reflect synchroneity. This is a result of changing climates and habitats in time. Consequently, proposed intracontinental correlations need confirmation based on magnetostratigraphy and a radioisotope time scale. Paleontologic characterizations of these land mammal ages (i.e. first and last record, and guide fossils) are useful for much of Argentina, but extensions to most of the other parts of South America are at best tenuous.
The majority of known non-Argentine Pleistocene faunas are believed to be Lujanian in age. Possible non Argentine early Pleistocene (Uquian) faunas include Ayo Ayo and Anzaldo in Bolivia, and Cocha Verde in southern Columbia. A possible middle Pleistocene (Ensenadan or early Lujanian) fauna is the Chichense of Ecuador. Paleomagnetic and radioisotopic date (MacFadden et al., 1983) clearly indicate that the greater part of the Tarija fauna (Bolivia) is Ensenadan in age.
The end of the Pleistocene and beginning of the Holocene in South America is marked by extinction of nearly all large mammalian herbivores and their specialized large predators. Radiocarbon age determinations suggest that large scale extinctions of megafauna occurred between 15,000 and 8,000 yrs. B.P. (years before present).
PV article infos
Published in Vol. 14, Ext (1984)
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Les gangas (Aves, Columbiformes, Pteroclidae) du Paléocène et du Miocène inférieur de France.
Published online: 11/02/1993
Keywords:
Birds; evolution; Lower Miocene; New taxa; Oligocene; Paleoecology; Paulhiac; Quercy Phosphorites; Saint-Gérand-Ie-Puy; Sandgrouse; Upper Eocene
https://doi.org/10.18563/pv.22.2-3.73-98
Abstract
The two species of Sandgrouse from Quercy, Pterocles validus MILNE-EDWARDS and P. larvatus MILNE-EDWARDS, are ascribed to the genus Archaeoganga MOURER-CHAUVIRÉ which includes a third, very large species, A. pinguis. The Sandgrouse of Saint-Gérand-le-Puy, Pterocles sepultus MILNE-EDWARDS, is ascribed to a new genus, Leptoganga. This form appears in the Upper Oligocene of Quercy, in Pech Desse and Pech du Fraysse localities, and is still present in the Lower Miocene of Saint-Gérand-le-Puy and Paulhiac. Recent Sandgrouse live in semidesert or desert areas. The indications provided by mammal and bird faunas in the localities where sandgrouse were found, confirm that the paleoenvironment was open and arid. The morphological study of these fossils indicates that, in the Upper Eocene, the Pteroclidae were already completely individualized with respect to Charadriiformes.
PV article infos
Published in Vol. 22, Fasc. 2-3 (1993)
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The Quaternary avifauna of Crete, Greece.
Published online: 01/09/1988
Keywords:
Avifauna; Crete; Quaternary; Systematics
https://doi.org/10.18563/pv.18.1.1-94
Abstract
Pleistocene bird fossils have been studied from nine localities on Crete. Part of this material was described earlier by the author (Weesie, 1982) and will not be treated here in extenso, the results will be incorporated. More than one third of the over 10,000 fossil bird bones available could be identified ; they were found to represent at least 65 bird species. The following species of the Pleistocene Cretan avifauna are new to the fauna of Crete : Branta ruficollis, Haliaeetus albicilla, Gyps melitensis, Aquila chrysaetos simurgh n. ssp., Ketupa zeylomensis, Aegolius funereus, Dendrocopos leucotos, Zoothera dauma, Turdus iliacus and Pyrrhula pyrrhula. The Pleistocene Cretan avifauna differs less from comparable mainland avifaunas than (fossil) avifaunas from oceanic islands do. Still, the Pleistocene Cretan avifauna has two qualities that are characteristic of island avifaunas : the almost complete absence of a group of birds (the Galliformes) and the presence of two endemic (sub)species : the giant eagle Aquila chrysaetos simurgh n. ssp. and the long-legged owl Athene cretensis (Weesie, 1982). The new subspecies is described in the present study.
These endemic birds of prey were found in association with their supposedly principal prey species (now extinct as well) : endemic mice for the owl and endemic deer for the eagle. Endemic mammals have been found in association with endemic birds of prey on many islands, not only in the Mediterranean. There is evidence that the size of endemic birds of prey becomes optimally adapted to their feeding on certain endemic mammals, especially rodents. Another characteristic of the Pleistocene Cretan avifauna is the great number of species of birds of prey. This appears to be a common characteristic of fossil avifaunas from caves on Mediterranean islands as well as from caves on the European mainland. However, we think that ecological conditions on Pleistocene Crete (especially the abundant presence of mice) helped to account for the high representation of birds of prey. Furthemore, the fossil avifauna enables us to draw some conclusions about the climate and vegetation on Pleistocene Crete : it is concluded that the climate was cooler than today and that Crete was largely covered with forests. Finally, the reasons for the extinction or disappearance from Crete of some bird species of the Pleistocene Cretan avifauna are discussed.
PV article infos
Published in Vol. 18, Fasc. 1 (1988)
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Contribution à l'étude des genres Gliravus et Microparamys (Rodentia) de l'Eocène d'Europe.
Published online: 15/03/1971
Keywords:
Eocene; Gliravus; Microparamys; Rodentia
https://doi.org/10.18563/pv.4.4.97-135
Abstract
Based on material found in about 15 localities the relationships of the genera Microparamys and Glirarus have been studied. One new genus, two subgenera and three species [Microparamys (Sparnacomys) chandoni n. subgen. and n. sp., Microparamys (Pantrogna) russelli n. subgen., Eoglirarus wildi n. gen. and n. sp., Gliravus meridionalis n. sp.] as well as the publication
of numerous new facts concerning species previously reported, support the phyletic scheme proposed. The latter shows that the origin of the Gliravinae is to be sought among the very small and still rather poorly known Microparamys species of the early Eocene. Gliravus: robiacensis can be considered as the common ancestor to different lineages not only of Glirarus but also of modern genera (Peridyromys, Glirudinus and Microdyromyx), at the origin of which Peridyromys micio, although difficult to interpret, occupies a similar place.
The stratigraphic conclusions permit more detail in the chronologie succession of the localities studied. The paleoecologic and biogeographic aspects lead one to the problem of the oligocene "Grande Coupure" through the study of this group.
PV article infos
Published in Vol. 04, Fasc. 4 (1971)
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The skull of Tetraceratops insignis (Synapsida, Sphenacodontia)
Published online: 09/01/2020
Keywords:
cranium; pelycosaur; Permian; therapsid origins
https://doi.org/10.18563/pv.43.1.e1
Abstract
Tetraceratops insignis is known from a single, crushed skull from the Lower Permian of Texas. Its unique proportions and osteological details gained central meaning in the question of the origins of Therapsida since this early synapsid has been determined as the oldest and less derived therapsid. Apart from Tetraceratops, the ‘mammal-like’ Therapsida and their sister, the pelycosaur-grade Sphenacodontidae, are separated by one of the longest ghost lineages in tetrapod fossil record. However, the minor, though well justified critique faced insistent publication regarding the therapsid hypothesis. A carefull re-evaluation of the holotypic skull reveals that therapsid traits cannot be supported, including a rejection of the formerly supposed adductor shelf in the temporal fenestra. Increased understanding of ‘pelycosaur’ character variation underlines a haptodontine-grade or, less likely, sphenacodontid position for Tetraceratops.
PV article infos
Published in Vol 43-1 (2020)
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Autopsie d’une radiation adaptative : Phylogénie des Theridomorpha, rongeurs endémiques du Paléogène d’Europe - histoire, dynamique évolutive et intérêt biochronologique
Published online: 15/12/2016
Keywords:
Diversification; Extinction; Paléoenvironnements; Rodentia; Theridomyoidea
https://doi.org/10.18563/pv.40.3.e1
Abstract
Résumé :
L’étude des rongeurs Theridomorpha permet de suivre le déroulement d’une radiation adaptative pendant toute sa durée (Eocène moyen-Oligocène terminal), sur un territoire restreint à l’extrémité ouest de l’Europe Occidentale. Dans ce papier, la phylogénie de ce groupe est établie à partir d’une analyse cladistique reposant sur l’examen de 315 caractères (310 dentaires). Le groupe d’intérêt comprend 110 des 132 espèces (24 genres) de Theridomyoidea et deux genres encore inclus jusqu’ici dans les Reithroparamyinae qui rejoignent les Theridomorpha. Les groupes externes comprennent des Glires basaux, Cocomys, Tanquammys et 16 Ischyromyiformes. Un cadre phylogénétique robuste est produit, qui permet de clarifier la systématique des Theridomorpha. La position des Remyoidea (nov. sup.fam.) au sein des Ischyromyiformes, extérieure aux Theridomorpha, est confortée. Les Protadelomys et Tardenomys sont à la base des Theridomyoidea, avant la séparation en deux clades correspondant aux familles Pseudosciuridae et Theridomyidae. Les sous-familles sont consolidées : Pseudosciurinae et Sciuroidinae pour les Pseudosciuridae ; Issiodoromyinae, Oltinomyinae, Columbomyinae, Theridomyinae, auxquelles s’ajoute au moins une nouvelle sous-famille (Patriotheridomyinae), pour les Theridomyidae. La topologie des chrono-espèces (sensu Simpson), traitées antérieurement comme lignées évolutives, apparaît dans la plupart des cas sous forme de clades successifs dans lesquels les espèces sont le plus souvent arrangées de manière pectinée, émergeant dans l’ordre stratigraphique. L’analyse des caractères aux principaux nœuds permet de consolider les caractères diagnostiques des taxons et les tendances évolutives, ainsi que de discuter des divers parallélismes et convergences dans l’évolution des structures et patrons dentaires (e.g., émail des incisives unisérié chez les Issiodoromyinae et les Patriotheridomyinae, ou pseudo-multisérié chez les Blainvillimys les plus hypsodontes, les Protechimys et Archaeomys ; patrons dentaires téniodontes ; allongement des dents déciduales chez les Patriotheridomyinae, Issiodoromyinae et Theridomyidae ; sélénodontie ou lophodontie). Les dynamiques évolutives traduites par les changements morphologiques sont mises en relation avec les variations environnementales. Enfin, les implications biochronologiques de l’évolution des Theridomyoidea sont discutées.
Abstract:
The adaptive radiation of the rodents Theridomorpha occurred during a limited time window (middle Eocene to late Oligocene), on an area restricted to Western Europe. In this paper, the phylogeny of this group is established via a cladistic assessment of 315 morphological characters (310 dental). The group of interest encompasses 110 upon 132 species (24 genera) of Theridomyoidea, and two genera formerly included within the Reithroparamyinae, and which are included here within the Theridomorpha. The outgroups include basal Glires, Cocomys, Tanquammys and 16 Ischyromyiformes. A robust phylogenetic frame is produced, which allows clarifying the systematics of the Theridomorpha. Within the Ischyromyiformes, the Remyoidea (nov. supfam.) are set apart from the Theridomorpha. Protadelomys and Tardenomys represent the earliest offshoots of the Theridomyoidea, before the dichotomy between Pseudosciuridae and Theridomyidae. It supports the former subfamilies Pseudosciurinae and Sciuroidinae within the Pseudosciuridae; and for the Theridomyidae: the Issiodoromyinae, Oltinomyinae, Columbomyinae, Theridomyinae, with at least one new subfamily (Patriotheridomyinae). The topologies of the chronospecies (sensu Simpson), formerly considered as evolutionary lineages, appear in most cases as successive clades, in which the species are generally pectinately arranged and emerging in the stratigraphic order. The analysis of characters supporting the main nodes allow consolidating the diagnosic characters of the taxa and their evolutionary trends, as well as discussing the various cases of parallelism and convergence in the evolution of structures and dental patterns (e.g., uniserial incisor enamel for Issiodoromyinae and Patriotheridomyinae, or pseudo-multiserial for the most hypsodont Blainvillimys, Protechimys and Archaeomys; taeniodont dental patterns; lengthening of deciduous premolars for Patriotheridomyinae, Issiodoromyinae and Theridomyidae; selenodonty or lophodonty).
Evolutionary dynamics are analysed with respect to environmental changes. Finally, biochronological implications of the evolution of Theridomyoidea are discussed.
PV article infos
Published in Vol 40-3 (2016)
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Decouverte d'un nouveau Diacodexis (Artiocactyla, Mammalia) dans l'Eocène inférieur de Silveirinha, Portugal.
Published online: 15/09/1989
Keywords:
Artiodactyla; Eocene; Migration; Portugal; Silveirinha
https://doi.org/10.18563/pv.19.1.29-44
Abstract
A new artiodactyl, Diacodexis antunesi n.sp., is described from the early Eocene of Silveirinha, Portugal. Comparisons are made with Diacodexis gazini GODINOT, 1978, D. varleti SUDRE et al., 1983, D. cf. varleti from Paris Basin sites, D. sp. from Dormaal and from localities in Spain and England, D. secans from North America and D. pakistanensis from Asia; affinities and evolutive tendencies are discussed. The presence of Diacodexis in the locality of Silveirinha confirms the very early Eocene age of the latter. As Diacodexis antunesi appears ta be more primitive than D. gazini from Rians (early Eocene of France), it lends corroboration to the interpretation (essentially based previously on condylarths) of the Silveirinha assemblage as the oldest Eocene fauna known in Europe and supports the hypothesis that early artiodactyls migrated from Europe to North America.
PV article infos
Published in Vol. 19, Fasc. 1 (1989)
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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 4 - Les artiodactyles Suidae.
Published online: 15/11/1988
Keywords:
Artiodactyla; France; Mammalia; Montredon; Upper Miocene
https://doi.org/10.18563/pv.18.ext.57-64
Abstract
There is only one suid known in the Upper Miocene of Montredon (Hérault): Microstonyx (Limnostonyx nov. subgen.) antiquus (KAUP). It is differenciated from Microstonyx major by the presence of upper and lower canines which are considerably longer and biger. Its presence at Montredon corroborates the palustrine habitat for the species.
PV article infos
Published in Vol. 18, Ext (1988)
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Macroscelidea, Insectivora and Chiroptera from the Miocene of east Africa.
Published online: 15/11/1984
Keywords:
Chiroptera; East Africa; Insectivora; Macroscelidea; Miocene; Systematics
https://doi.org/10.18563/pv.14.3.117-198
Abstract
The East African Miocene Macroscelidea, lnsectivora and Chiroptera are revised on the basis of new material. New taxa proposed are: Miorhynchocyon, .n. gen. (Macroscelididae): Míorhynchocyon meswae, n. sp.: Pronasílío ternanensis. n. gen.. n. sp. (Macroscelididae); Hiwegicyon juvenalis, n. gen. n. sp. (Macroscelididae); Parageogale, n. gen. (Tenrecidae): Prochrysochlorinae, n. subfam. (Chrysochloridae): Propottininae, n. subfam, (Pteropodidae); Chamtwaria pickfordi, n. gen., n. sp. (Vespertilionidae). Gymnurechnínus songhorensis is synonymised with G. camptolophus. The new material provides additional information on the dentition, especially of Myohyrax oswaldi. Galerix africanus. Amphechínus rusingensis, Protenrec tricuspis and Parageogale aletris. Partial skulls are described of Amphechinus rusingensis, Protenrec tricuspis, Prochrysochloris míocaenicus and Taphozous incognita. The oldest member of the Macroscelidinae (Pronasilio) is described from Fort Ternan. Galerix africanus is closely related to G. exilis from Europe. Amphechinus rusingenesis is compared with Asiatic Oligocene Erinaceinae. The Miocene age of Crocidura is rejected. On the evidence of humeri, the following families of Chiroptera are newly reported: Pteropodidae, Nycterididae, Vespertilionidae, Molossidae. Propotto is regarded as an offshoot from the Pteropodidae, not ancestral to modern forms. Chamtwaria is a primitive vespertilionoid, provisionally placed in the Kerivoulinae. Erinaceidae probably entered Africa at the beginning of the Miocene, before 20 Ma. Faunistic differences between deposits are largely to be ascribed to differences in local environment.
PV article infos
Published in Vol. 14, Fasc. 3 (1984)
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A late Eocene palaeoamasiine embrithopod (Mammalia, Afrotheria) from the Adriatic realm (Island of Rab, Croatia)
Published online: 14/12/2023
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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Contributions à l'étude du gisement Miocène supérieur de Montredon (Hérault). Les grands mammifères. 3 - Les artiodactyles ruminants
Published online: 15/11/1988
Keywords:
Artiodactyla; France; Montredon; Ruminentia; Upper Miocene
https://doi.org/10.18563/pv.18.ext.43-56
Abstract
The remains of Ruminantia are very rare at Montredon. No specific determination was possible. We have only one Micromeryx, one small cervid, one tragocere and one (?) gazella. The faunal spectrum is in good correlation with the general retreat of the cervids in the European upper Miocene, but in contrast it is not convenient for the bovids, which are in expansion at the same time. For them, we have to invoke the local ecological conditions.
PV article infos
Published in Vol. 18, Ext (1988)
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Les Gruiformes (Aves) des phosphorites du Quercy (France). 1. sous-ordre cariamae (Cariamidae et Phorusrhacidae), systématique et biostratigraphie.
Published online: 30/11/1983
Keywords:
Aves; Biostratigraphy; Birds; Cariamae; gruiformes; Quercy Phosphorites; Systematics
https://doi.org/10.18563/pv.13.4.83-143
Abstract
The revision of the old collections of fossil birds from the “Phosphorites du Quercy” and the study of new material give the following results (Gruiformes, Cariamae) : The humeri and most of the carpometacarpi described under the name Filholornis belong in Elaphrocnemus. The ulnae ascribed to Fïlholornis belong in Idiornis. Most of the post-cranial elements of the genera Elaphrocnemus and Idiornis are described and show great similarities with recent Cariamidae and Opisthocomidae, and fossil Bathornithinae. A new genus and a new species, Oblitavis insolitus, are created in the sub-family Idiornithinae; two new species are described in the genera Elaphrocnemus (E. brodkorbz) and Idiornis (I. itardiensis), and the species Elaphrocnemus gracilis is transferred to the genus Idiornis. The genus Propelargus Lydekker is transferred from the family Ciconiidae to Cariamidae. A new generic name, Occitaniavis, is created for the species Geranopsis elatus, which belong in Cariamidae, while the type-species of the genus, Geranopsis hastingsiae, is a member of the Gruidae. The affinities between the Quercy avifauna and the Neotropical one is emphasized by the occurrence of Phorusrhacidae, previously known only from the Cenozoic of South America and the Late Pliocene or Early Pleistocene of North America. Thanks to the material collected during the new excavations, the stratigraphical position of most of the species is stated precisely, and evolutionary lineages are outlined. This study shows that the suborder Cariamae, presently restricted to two South American genera, was already extremely diversified during the Eocene, and widespread in Europe and North America.
PV article infos
Published in Vol. 13, Fasc. 4 (1983)
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Le genre Plagiolophus (Palaeotheriidae, Perissodactyla, Mammalia): révision systématique, morphologie et histologie dentaires, anatomie crânienne, essai d'interprétation fonctionnelle
Published online: 15/12/2004
Keywords:
New taxa; Paléogène; perissodactyls; skull anatomy; tooth histology
https://doi.org/10.18563/pv.33.1-4.17-281
Abstract
The genus Plagiolophus is documented, almost solely in Western Europe, from the middle Eocene up to the mid Oligocene (MP 12 to MP 25), i.e. more than for 15 MY. Seventeen species are now recorded whose two of them are new, P. ringeadei nov. sp. and P. mamertensis nov. sp. Some anatomical variations and the deflection of certain evolutionary trends justify the distinction of three subgenera, Paloplotherium, Fraasiolophus nov. and Plagiolophus s.s. The genus displays a wide range in size and weight (between 10 and 150 kg). The detailed description of the skull of several species is here given for the first time.
Despite important evolutionary drifts during this long time span, the dentition shows a great structural homogeneity, which renders difficult the determination of fragmentary specimens or isolated teeth. It is characterized by a great heterodonty; premolars are little molarized and present a certain regression through time with paradoxically some progress in the molarization. The hypsodonty increases: the first Plagiolophus are hardly less brachyodont than Propalaeotherium, and the last ones are nearly as hypsodont as Merychippus from the early Miocene. The upper molars change from a wide crown pattern, with an open occlusal surface, lightly oblique transverse lophs and rounded internal cusps, to a narrower pattern, with a frontally constricted occlusal surface and internal lophs aligned parallel to the ectoloph. The M3/3 become always longer.
The dental enamel displays horizontal Schreger-bands with imprecise limits occupying only the middle part of the enamel layer. The dentine is remarkable by its high rate of pericanalicular dentine. The crown cementum, lacking in earlier forms, increases to the point where it fills the occlusal valleys of the
teeth.
The masticatory musculature shows a increasing prominence of the temporal, with probably an important role devoted to the pterygoid muscles in lateral movements related to a two-phase type of chewing.
The evolution of the dentition, of the masticatory musculature and of the repartition of masticatory forces indicate that the Plagiolophus have known different diets through their long evolutionary history; at first browsers they became mixed feeders and finally grazers. Their relatively long neck allowed these animals to reach different vegetal layers. The strength of the nuchal crests also suggests that they were able to have strong backwards movements of the head to pull up their food.
This evolution of diet seems related to the slow degradation of environmental conditions attested during this period in western Europe, with the generalization of more open landscapes, increasing aridity and more marked seasons.
Besides, a remodeling of the face is ontogenetically and along time observed, in relation with the evolution of the masticatory apparatus and especially with that of the mandibular lever arm. The postcanine diastemata become longer in the course of evolution; the free extremities of the nasals are always relatively long which contradicts the hypothesis according to which Paloplotherium may have had a trunk. At last the lineage Fraasiolophus can be distinguished by the presence of a deep malar fossa, probably related to a strong development of the maxillo-labialis superior muscle.
The orbit is always large and tends to increase in size, which indicates a good development of the vision and its increasing role in the life relations. A peculiar type of epitympanic sinus could have been used as a resonance chamber insuring a certain amplification of sounds before their transmission to the eardrum. The endocranial cast reveals a relatively large brain with an advanced degree of gyrencephaly. Beside the role eventually played in food research and social relations, these neurophysiological abilities, also related to an advance in cursorial fitness, could have contributed to the survival of these animals facing the predation pressure of the first fissipede carnivores and the competition with new immigrant herbivores after the "Grande Coupure".
On the basis of some shared apomorphies with the Pachynolophinae, which prevent from considering the latter as Equidae (molarization of the premolars, reduction of the premaxilla dorsal apophysis, peculiar epitympanic sinus, splitting of the jugular process), the hypothesis of an autochthonous origin of Plagiolophus issued from a form near Propalaeotherium, is once again proposed and discussed. Finally, intra-generic relationships are taken into consideration.
PV article infos
Published in Vol. 33, Fasc. 1-4 (2004)
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Terrestrial vertebrate paleocommunities from the Cerro del Pueblo Formation (Late Cretaceous; Late Campanian) at Las Aguilas, Coahuila, Mexico
Published online: 16/07/2019
Keywords:
Campanian; Coahuila; dinosaurs; Mexico.; Vertebrates
https://doi.org/10.18563/pv.42.2.e1
Abstract
The Las Águilas site near Porvenir de Jalpa, Coahuila, Mexico, is extremely rich in tetrapod remains comprising both bones and trackways of several dinosaur taxa of late Campanian age. Within a 50 m thick section we identified at least nine layers with dinosaur bone assemblages. In one of these the dinosaur bones are associated with remnants of eusuchian crocodilians, turtles, plesiosaurs, pterosaurs, tyrannosaurids, dromaeosaurids, parksosaurid, hadrosaurids, ceratopsids, and ankylosaurs. This layer is also rich in coprolites of turtles, crocodilians and likely theropods, thus providing evidence for the wealth of Late Cretaceous vertebrate life in the area.
PV article infos
Published in Vol 42-2 (2019)
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Die Ohr-Region der Paulchoffatiidae (Multituberculata, Ober-Jura).
Published online: 15/11/1988
Keywords:
Multituberculata; Ober-Jura; Paulchoffatiidae; Petrosum; Portugal
https://doi.org/10.18563/pv.18.3.155-185
Abstract
The petrosal of the Paulchoffatiidae HAHN, 1969 is described and compared with that of younger multituberculates and of other Mesozoic mammals. The "Morrison petrosal", described by Prothero (1983), is also discussed; it probably belongs to the multituberculates. The reconstruction of the ventral side of the Paulchoffatiinae-skull, given by Hahn in 1987, is completed by addition of the otic and the occipital region.
PV article infos
Published in Vol. 18, Fasc. 3 (1988)
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Norselaspis glacialis n.g., n.sp, et les relations phylogénétiques entre les kiaeraspidiens (Osteostraci) du dévonien inférieur du Spitsberg.
Published online: 15/06/1981
Keywords:
Devonian; kiaeraspids; Osteostraci; Spitsbergen
https://doi.org/10.18563/pv.11.2-3.19-131
Abstract
The anatomy of Norselaspis glacialis n.g., n.sp., a primitive kiaeraspidian from the Lower Devonian of Spitsbergen, is described on the basis of spécimens studied by grinding sections or prepared with dilute formic acid. This study yielded some new anatomical details, including the presence of a canal prolonging posteromedially the canal alloted to the facial nerve by Stensiö. This posterior prolongation of the « facial canal ›› into the posterolateral part of the labyrinth cavity is consistent with the hypothesis put forward by Allis, Lindström, Jefferies and Whiting, that this canal housed the glossopharyngeus nerve. Furthermore, in N. glacialis, the foramen usually referred to as the foramen for the œsophagus opens posteriorly into a cavity in the postbranchial wall, referred to here as the intramural cavity, and which is interpreted as having housed the heart. Consequently, the œsophagus probably accompanied the dorsal aorta through the aortic canal. Finally, the foramen generally interpreted as having transmitted the ventral afferent arterial trunk is here considered as having housed the hepatic vein, which emptied into the venous sinus of the heart. The ventral afferent arterial trunk may thus have passed through the former «œsophageal ›› foramen.
The problem of the position of the dorsal nerves in the Osteostraci is discussed, and it is suggested that the three foremost nerve canals opening into the oralobranchial cavity housed the maxillary ramus of the trigeminus, the facial nerve and the glossopharyngeus nerve respectively. The mandibular ramus of the trigeminus must have accompanied one of the two foremost nerves, but for the moment it is impossible to decide which.
The problem of the nature of the interbranchial crests of the Osteostraci is briefly discussed. Comparison with the branchial apparatus of the Petromyzontida does not support the hypothesis that the interbranchial crests are part of the branchial arches, incorporated into the endoskeletal shield. A different hypothesis is proposed, that the branchial skeleton of the Osteostraci was situated entirely inside the oralobranchial cavity, and was attached to the endoskeletal shield only by the ventromedial processes. The grooves classically allotted to the efferent branchial arteries would thus have housed extrabranchial arteries, branching off from the dorsal aorta, and irrigating the ventral branchial musculature.
A phylogeny and a classification of the kiaeraspidians are proposed. The evolution of this monophyletic group is characterized by, e.g., reduction of cornual processes, shortening of the abdominal division of the shield, subdivision of the lateral fields, and enlargement of the supraoral fossae.
The phylogenetic position of the kiaeraspidians within the Osteostraci remains uncertain. Their sister-group may be either the benneviaspidiens or the thyestidians, or Thyestes alone (in which case they would have to be included within the thyestidians).
PV article infos
Published in Vol. 11, Fasc. 2-3 (1981)
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Batoids (Rajiformes, Torpediniformes, Myliobatiformes) from the Sülstorf Beds (Chattian, Late Oligocene) of Mecklenburg, northeastern Germany: a revision and description of three new species
Published online: 24/06/2015
Keywords:
Batoids; Chattian; Elasmobranchii; North Sea Basin; Oligocene
https://doi.org/10.18563/pv.39.2.e2
Abstract
Bulk-sampling of fossil-rich tempestites from the Chattian Sülstorf Beds of
Mecklenburg, north-eastern Germany, yielded a rich selachian fauna in which batoids
predominate by the abundance of teeth but are subordinate by the number of taxa. Thirteen
taxa are identified, among which rajiform batoids are the most diverse (six species). One
genus and three species are newly described: Raja thiedei sp. nov., Oligoraja pristina gen. et
sp. nov., and Torpedo chattica sp. nov. Two species are reallocated: Atlantoraja cecilae
(Steurbaut & Herman, 1978) new comb., and Dipturus casieri (Steurbaut & Herman, 1978)
new comb. Ontogenetic heterodonty is documented for the first time in the dental pattern of
Myliobatis sp. Stratigraphical ranges of batoid taxa in the period from Rupelian to Langhian
are presented and partly discussed in context with the palaeoclimatic evolution and
palaeogeographic situation of the North Sea Basin.
PV article infos
Published in Vol.39-2 (2015)
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Old world hemiones and new world slender species (Mammalia, Equidae)
Published online: 16/12/2008
Keywords:
Amerhippus; biometry; Equus; Holocene; New World; Old World; Osteology; Pleistocene; Pliocene
https://doi.org/10.18563/pv.36.1-4.159-233
Abstract
Morphological and biometrical description of skulls, teeth, and limb bones of extant and fossil Old World herniones (including E. hydruntinus) and of New World 'stilt-Iegged' and other slender species from Blancan to Holocene. An Appendix presents ways in which the approximate size of some missing bones or dimensions may be deduced from available ones.
The discussed and/or illustrated fossils were found in Bolivia (Tarija), Canada (Yukon), China (Choukoutien, Gulongshan, Jiling, Loufangzi), Ecuador (Oil Fields), Ethiopia (Melka Kunturé), France (Lunel-Viel), Germany (Süssenborn), Greece (Agios Georgios, Petralona), Hungary (Dorog), Italy (Romanelli), Mexico (Cedazo, San Josecito), Mongolia (Sjara-osso-gol), Spain (Venta Micena), ex-Soviet Union (Akhalkalaki, Binagady, Chokurcha, Chukochya, Kabazi, Kolyma, Krestovka, Kurtak, Staroselie, Tologoj), USA (Alaska, Arkalon, Cedar Meadow, Channing, Conkling, Dry Mountains, Hay Springs, Leisey Shell Pit A, Lissie Formation, Natural Trap, Pool Branch, Powers Ranch, Rock Creek, San Diego, Santo Domingo, Seymour Formation, Shelter, Slaton, Trinity River). Numerous raw or statistically elaborated data are given in Tables.
There is no evidence for the existence of Old World hemiones in the New World nor of 'stilt-Iegged' equids in the Old World. The first 'stilt-Iegged' equid was found at Santo Domingo, New Mexico, and is believed to be Late Blancan. It was probably at the origin of E. calobatus (Arkalon, Rock Creek) and of the smaller E. semiplicatus (Channing, Rock Creek). Slender, but not 'stilt-Iegged', equids found at Natural Trap, Wyoming, ca. 12 ky ago belong to Amerhippus. AlI these species share with Oid World Sussemiones (and some hemiones) peculiar patterns on the lower cheek teeth.
The slender Equus sp. B of Leisey Pit A, Florida, ca. 1.2 Ma, as weIl as Amerhippus francisci and E. tau (probably a senior synonym of E. quinni) share conventional lower cheek teeth patterns. The skulls of A. francisci and E. tau, however, are quite different.
Paleontological data suggest a common origin of Amerhippus, Sussemiones, and 'stilt-Iegged' equids during the late Blancan. Old World hemiones seem to have differentiated later.
PV article infos
Published in Vol. 36, Fasc. 1-4 (2008)
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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: 03/01/2022
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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