Print ISSN: 0031-0247
Online ISSN: 2274-0333
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stratigraphy and biochronology of Oligo-Miocene of Kazakhstan
Eocene otoliths (Clinchfield Formation), Georgia
Fossil snakes, Palaeocene, Itaborai, Brazil, Part I
Notidanodon tooth (Neoselachii: Hexanchiformes) in the Late Jurassic of New Zealand
Abstract book of the 18th Conference of the EAVP
Eocene (57) , Quercy Phosphorites (38) , Systematics (32) , Rodents (29) , Mammalia (27)
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Cryptomerix Schlosser, 1886, Tragulidé de l'oligocène d'Europe ; relations du genre et considérations sur l'origine des ruminants.Jean SudreKeywords: Archaic Ruminants; Paleobiogeography; Quercy Phosphorites; Systematics; TragulidsAbstract The genus Cryptomeryx SCHLOSSER, 1886, inusited during a long period, has been discovered in Lower and Middle Oligocene localities of the Quercy region (South-West France). This new material, as well as specimens from the old collections referred to Cryptomeryx, are described; their study, allows us precising the definition of the genus, and confirming its allocation to the Tragulidae family. The type species of the genus, Crypmmeryx gaudryi (= Lophiomeryx gaudryi FILHOL, 1877), occurs in several localities at the base of the Middle Oligocene (Itardies, La Plante 2, Roqueprune 2, Soulce, Herrlingen 1). The new species C. matsoui n. sp. has been defined in the older locality of Mas de Got (top of Lower Oligocene). It is possible that the species Pseudamphimeryx decedens STEHLIN, 1910 pertains to the same genus. Also to the Tragulids must be referred the monospecific genus Iberomeryx (I. parvus GABOUNIA, 1964) from Upper Oligocene of Benara (Georgie, URSS), with which Cryptomeryx is related. These genera are not direct ancestors of Miocene tragulids; their occurrence in the Western European Oligocene results from a first immigration wawe of the family. These Tragulids are one of the most archaic groups of Ruminants. They are probably derived from a primitive stock which had acquired in Asia the selenodont condition of the dentition. Article infos Published in Vol. 14, Fasc. 1 (1984) |
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Revision of the family Cephalomyidae (Rodentia, Caviomorpha) and new cephalomyids from the early Miocene of Patagonia.Alejandro KramarzKeywords: Cephalomyidae; Lower Miocene; Patagonia; Rodentia; Soriamys; SystematicsAbstract A new genus of hystricognath rodent with two new species, Soriamys gaimanensis and Soriamys ganganensis, from the Colhuehuapian Age (Early Miocene), Sarmiento Formation, of Patagonia is described. The first species comes from the south barranca of the valley of Rio Chubut, near Gaiman locality (Chubut Province). It is known through a great number of dental remains in different stages of wear. The teeth are protohypsodont, with cement in the principal valleys. P4 are simpler, more oval inoutline and without a differentiated hypocone-hypoflexus. Upper molars are pentalophodont in early stages of wear and become bilobated in middle and advanced stages; M3 have a temporary third posterior lobe due to the maintenance of the braquiflexus on the posterior wall of the tooth. Lower teeth have a completely asymrnetrical pattern in relation to the uppers. The molars are trilophodont, with only one complex crest in the trigonid composed of the fusion of the anterolophid and mesolophid. The dp4 have a derived pentalophodont pattern due to the loss or fusion of the mesolophid and the development of an accessory transverse crest between the anterolophid and metalophid. The second species is known through a complete skull and jaw and other skull fragments with the dentition, proceeding from Pampa de Gan Gan, Chubut province. Respect to the first species, the teeth are higher crowned, with an earlier occlusal simplification and a third posterior lobe of M3 more developed and persistent. The skull and jaws show many chinchilloid characters, such as jugal bone with an ascending process, concave palate, very prominent dorsal shelf of the masseteric fossa, nasolachrymal duct opened laterally on the maxillary and very developed lateral mandibular fossa. Moreover, Soriamys is closely related to Cephalomys by sharing a similar asymmetric dental pattern and other dental and mandibular characters. These two genera constitute a natural group, the Cephalomyidae, with peculiar dental characters, like the asymmetric pattem of the upper and lower teeth; Cephalomyopsis, and probably Litadontomys, can be considered part of this group. Scotamys and Perimys constitute a distinct lineage (the Neopiblemidae or Perimyidae), more closely related to the chinchillids. Many characters shared by cephalomyids, eocardiids and caviids suggest a closer affinity between the Chinchilloidea and the Cavioiidea as a whole. Abrocoma shows also an asymmetric dental pattern and other chinchilloid features that suggest some degree of relationship with the cephalomyids, still not well determined. Article infos Published in Vol. 30, Fasc. 1-2 (2001) |
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The evolution of the molar pattern of the Erethizontidae (Rodentia,Hystricognathi) and the validity of Parasteiromys Ameghino, 1904.Adriana M. CandelaKeywords: Argentina; Erethizontidae; Hystricognathi; Miocene; Molar evolution; Porcupines; Rodentia; SystematicsAbstract The genus Parasteiromys AMEGHINO, 1904 is revalidated, and P. friantae sp. nov. (Hystricognathi, Erethizontidae) from Colhuehuapian (early Miocene) sediments of the southern cliff of Colhue-Huapi Lake (Province of Chubut, Argentina), is described. The molar morphology of these taxa and of living porcupines adds new elements to understand the dental evolution of the Erethizontidae, and to propose the hypothetical ancestral molar pattern for this family. This pattern does not correspond to any of the morphologies traditionally proposed as ancestral for South American hystricognathous rodents. The proposed pattern is characterized by a metaloph disconnected from the posteroloph and oriented towards the hypocone, and the third loph incompletely developed with the lingual portion homologous to the mesolophule of Baluchimyinae (Chapattimyidae) from the Miocene of Pakistan. The inferred steps of the molar evolution of erethizontids towards the pentalophodont condition, considered derived for the family, are illustrated. This study strengthens the hypothesis placing erethizontids in a basal position among rodents of the suborder Hystricognathi. Article infos Published in Vol. 28, Fasc. 1 (1999) |
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Nouvelles données sur les mammifères du Thanétien et de l'Yprésien du bassin d'Ouarzazate (Maroc) et leur contexte stratigraphique.Emmanuel Gheerbrant, Jean Sudre, Sevket Sen, Claude Abrial, Bernard Marandat, Bernard Sigé and Monique Vianey-LiaudKeywords: early Paleogene; magnetostratigraphy; Mammals; Morocco; North Africa; Ouarzazatz basin; SystematicsAbstract New faunal and stratigraphical data on the vertebrates localities from the early Paleogene of the Ouarzazate Basin (Adrar Mgorn 1, Adrar Mgorn 1 bis et N'Tagourt 2), Morocco, are presented. A magnetostratigraphical study, the first for such early Paleogene Arabo-African mammal localities, and the discovery of probable remains of the nannofossil Discoaster support the Thanetian age of the Adrar Mgorn 1 site. The magnetostratigraphy suggests a slightly later age than was thought for the Paleogene formations of the local series of Tinerhir and for the vertebrate localities: late or latest Thanetian for Adrar Mgorn 1 and Adrar Mgorn 1 bis, middle Ypresian for N'Tagourt 2. It also indicates a lower position of the KT boundary in the series. Two tons of matrix recovered in the vertebrate sites have vielded new data on the micromammals. A damaged lower molar from N'Tagourt 2 is referable to Khamsaconus bulbosus and supports the proboscidean affinities of this species and especially possible relationships with bunolophodont taxa such as elephantiforms. A lower molar from Adrar Mgorn 1 bis belongs to a new form which can be identified as a plesiadapiform or an euprimate close to Altiatlasius koulchii though significantly larger. A new material from Adrar Mgorn 1 illustrates a new dilambdodont adapisoriculid species which is referable to Garatherium : ?Garatherium todrae n. sp. Another species referred to Garatherium is known in the locality (?Garatherium n. sp.). Garatherium is a new lineage from the Ouarzazate basin which crosses the Paleocene-Eocene boundary together with Palaeoryctes, Didelphodontinae gen. and sp. 2, Todralestes, and Afrodon, and it is the first Paleocene-Eocene lineage identified outside of this basin (Garatheríum is based on a species from El Kohol, Algeria). Among the Paleocene-Eocene lineages from the Ouarzazate basin, it should be also mentioned a new possible carnassial form (carnivoran or creodont; Adrar Mgorn 1), and an upper molar of Cimolestes cf. incisus (Adrar Mgorn 1 bis). The upper molar THR 168 previously reported as from an indeterminate didelphodontine is here identified as the M1/ of Afrodon chleuhi. The micromammal faunas from the Ouarzazate basin are positioned in the global chronological framework of the mammal localities from the Paleogene of the Arabo-African domain. Article infos Published in Vol. 27, Fasc. 3-4 (1998) |
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New datation of the Tafna Basin (Algeria): A combination between biochronological and magnetostratigraphical dataSalamet Mahboubi, Mouloud Benammi and Jean-Jacques JaegerKeywords: correlations; Late Miocene; North Africa; Rodentiadoi: 10.18563/pv.39.1.e1 Abstract The Tafna Basin corresponds to the lowlands, which are located in front of Tessala and Traras ranges, below the Tlemcen mountains, Algeria. This basin displays a complete sedimentary cycle dominated by lagoonal-fluvial and marine deposits. The continental formations located at the base of these deposits are mainly composed of alternating sandstones and clays. An early late Miocene age has been previously attributed to them, based on direct correlations with marine deposits. Search for micromammal fossils led to the discovery of three different rodent species from a single level of the Djebel Guetaf section, located at the bottom of these deposits. The rodent assemblage indicates a late Miocene age. Combined magnetostratigraphical and biostratigraphical investigations were carried out to provide a more accurate age control of these continental deposits. Sixty-four oriented rock samples were collected for a magnetostratigraphic study along a 92 meters thick section including the fossiliferous layer. Rock magnetic investigations indicate the presence of both high and low coercivity minerals. Specimens subjected to progressive thermal demagnetization procedures show that the samples exhibit a high temperature magnetization component and display a normal polarity. Based on biostratigraphic constraints, the Guetaf section is correlated with Chron C4An, indicating an age ranging from Article infos Published in Vol.39-1 (2015) |
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A new species of hippopotamine (Cetartiodactyla, Hippopotamidae) from the late Miocene Baynunah Formation, Abu Dhabi, United Arab EmiratesJean-Renaud Boisserie, Mathieu Schuster, Mark J. Beech, Andrew Hill and Faysal BibiKeywords: Arab Peninsula; Hippopotamidae; Hippopotamine event; Systematicsdoi: 10.18563/pv.41.1.e2 Abstract The discovery of new hippopotamid material from the late Miocene Baynunah Formation (Abu Dhabi, United Arab Emirates) has prompted the revision of the existing material of this as yet unnamed fossil taxon. The Baynunah hippopotamid appears to be distinct from all other contemporary and later species in having a relatively more elongate symphysis, a feature similar to the earlier (and more primitive) Kenyapotamus. Yet, the Baynunah hippopotamid presents a dentition typical of the Hippopotaminae. It is therefore a distinct species attributed to the later subfamily, described and named in this contribution. This species provides further evidence for a ca. 8 Ma evolutionary event (termed “Hippopotamine Event”) that initiated the spread and ecological significance of the Hippopotaminae into wet habitats across Africa and Eurasia. The morphological affinities of the new species from Abu Dhabi suggest that the Arabian Peninsula was not a dispersal route from Africa toward southern Asia for the Hippopotamidae at ca. 7.5 Ma to 6.5 Ma. Article infos Published in Vol 41-1 (2018) |
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Neolicaphrium recens Frenguelli,1921,the only surviving proterotheriidae (Litopterna, Mammalia) into the south american Pleistocene.Mariano Bond, Daniel Perea, Martin Ubilla and Adan TauberKeywords: Litopterna; Neolicaphrium recens; Pleistocene; Proterotheriidae; South AmericaAbstract The litoptem Proterotheriidae are extinct endemic South American ungulates frequently used as an example of evolutionary convergence with the horses. They were considered to be exclusively Tertiary representatives with the youngest record being in the late Pliocene, before the appearence of the equids and cervids during the Great American Interchange. Two undoubted Pleistocene records in Argentina and the specimen here described from Uruguay, confirm the persistence of the proterotherids into that period. In the Quaternary, these ungulates are found outside the typical pampean region and probably were confined to a few northern and warmer more forested relictual microhabitats. Article infos Published in Vol. 30, Fasc. 1-2 (2001) |
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The new Algerian locality of Bir el Ater 3: validity of Libycosaurus algeriensis (Mammalia, Hippopotamoidea) and the age of the Nementcha FormationFabrice Lihoreau, Lionel Hautier and Mahammed MahboubiKeywords: Dispersal event; Miocene; North Africa; Tetralophodondoi: 10.18563/pv.39.2.e1 Abstract The description of original material of anthracothere and proboscidean in the new locality of Bir el Ater 3 from East Algeria, and a thorough review of early Libycosaurus remains of Bir el Ater 2 allows us validating L. algeriensis as the smallest and earliest species of Libycosaurus and probably the earliest migrant of the genus from Asia. The presence of a Tetralophodon in the Neogene Nementcha formation might represent the earliest occurrence of the genus in Africa. These original fossil remains allow us to discuss the age of the Neogene part of the Nementcha formation close to the Serravalian/Tortonian boundary. Article infos Published in Vol.39-2 (2015) |
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Les gisements de Robiac (Eocène supérieur) et leurs faunes de Mammifères.Jean SudreKeywords: Fauna; Late Eocene; Mammalia; Robiacdoi: 10.18563/pv.2.3.95-156 Abstract Designated the type-locality of a late Eocene paleomammal zone, Robiac has recently been the object of important excavations. The first results of the new collecting, as well as a revision of the material in old collections, are given in this work. Article infos Published in Vol. 02, Fasc. 3 (1969) |
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Un giraffidae dans le pliocène de Montpellier ?Claude GuérinKeywords: Artiodactyla; France; Giraffidae; Mammalia; Montpellier; RuscinianAbstract An upper giraffid premolar without any indication about its origin is preserved at the Montpellier University among numerous fossils from the ruscinian formation of Montpellier. It can be related to Samotherium, of the Upper Miocene in Eastern Europe, North Africa and Asia, or more probably to Bramatherium or Hydaspitherium of the Pliocene of South East Asia. The sedimentological study of the matrix shows a calcareous background, which may indicate that this tooth does not come from the Montpellier formation. Article infos Published in Vol. 16, Fasc. 3 (1986) |
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La poche à phosphate de Ste-Neboule (Lot) et sa faune de vertébres du Ludien Supérieur. 1 La poche et son remplissageBernard GèzeKeywords: Eocene; Quercy PhosphoritesAbstract La poche de Ste-Néboule, commune de Béduer (Lot), 15 km environ à l'WSW de Figeac, fait partie du groupe le plus septentrional des gouffres creusés par les ruissellements du Paléogène dans les calcaires jurassiques de la bordure sud-ouest du Massif Central et qui furent comblés à la même époque par des argiles sidérolithiques accompagnées de phosphate de chaux concrétionné ainsi que des restes de la célèbre faune dite «des phosphorites du Quercy» . Article infos Published in Vol. 08, Fasc. 2-4 (1978) |
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Analysis of mammalian communities from the late Eocene and Oligocene of southern FranceSerge LegendreKeywords: Late Eocene; Mammalian communities; Oligocene; Quercy; Southern FranceAbstract Valverde's cenogram method is used to analyse mammalian communities from the late Eocene to late Oligocene of southern France, mainly from the "Phosphorites du Quercy". Cenogram analysis involves plotting the size of each component species in a fauna on a semilog diagram in rank order, permitting fossil faunas to be compared with Recent ones. The configurations of Recent communities serve as models for establishing the general environmental characteristics of fossil mammalian faunas. This method of analysis applied to faunal sequence can reveal major and sudden ecological perturbations. The paleobiogeographical event (i.e. the mammalian immigration wave) at the Eocene-Oligocene Boundary in western Europe, known as the «Grande Coupure", is here shown to represent a drastic and sudden ecological change: late Eocene tropical environments in Europe deteriorated rapidly turning to subdesert or desert environments al the beginning of the Oligoccne. Article infos Published in Vol. 16, Fasc. 4 (1986) |
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Description des rongeurs Pliocènes de la faune du Mont-Hélène (Pyrénées-Orientales, France), nouveau jalon entre les faunes de Perpignan (Serrat-d'en-Vacquer) et de Sète.Jean-Pierre Aguilar, Marc Calvet and Jacques MichauxKeywords: Chronology; Climatology; France; Mont-Hélène; Pliocene; RodentsAbstract The Mont-Hélène's fauna [Pyrénées-Orientales, France], includes 15 species of rodents with a new one, Occitanomys montheleni n. sp. among the 9 species of the Murids which are listed. The uncommon Cricetid, Blancomys neglectus, is well represented in the fauna. Peculiarities of the population referred to Slephanomys cf. donnezaniare discussed. The locality a fissure filling may be the oldest one of Tabianian age known in Southern France. The diversity of the Murids gives evidence of a subtropical climate and of a diversified environment which may be linked to the spreading of the coastal plain following the filling up of the Roussillon Neogene Basin. Article infos Published in Vol. 16, Fasc. 3 (1986) |
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An Australian Miocene Brachipposideros (Mammalia, Chiroptera) related to Miocene representatives from FranceBernard Sigé, Suzanne J. Hand and Michael ArcherKeywords: Australia; bats; Chiroptera; MioceneAbstract A new middle Miocene hipposiderid bat is described from a limestone deposit on Riversleigh Station in north-western Queensland. Hipposideros (Brachipposideros) nooraleebus n. sp. is the first record of this subgenus from anywhere in the world outside of France. The palaeoecological setting of the fossil bats appears to have been a relatively quiet, sunny lime-enriched tropical pool that contained tortoises, crocodiles and fish. It is possible that the bats were washed into the pool from an adjacent cave. Article infos Published in Vol. 12, Fasc. 5 (1982) |
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First record of dinosaur eggshells and teeth from the north-west african Maastrichtian (Morocco).Géraldine Garcia, Rodolphe Tabuce, Henri Cappetta, Bernard Marandat, Ilhem Bentaleb, Aziza Benabdallah and Monique Vianey-LiaudKeywords: Africa; amniotic eggshells; Maastrichtian; Morocco; theropod teethAbstract 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. Article infos Published in Vol. 32, Fasc. 2-4 (2003) |
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La poche à phosphate de Ste-Néboule (Lot) et sa faune de vertebres du Ludien supérieur. 7- Didelphides (Marsupiaux)Jean-Yves CrochetKeywords: Eocene; Quercy PhosphoritesAbstract The family Didelphidae is represented by three species in the Sainte-Néboule site, phosphorites of Quercy (lower Oligocene, San Cugat's nivel): Amphiperatherium minutum (Aymard), Amphiperatherium sp. and Peratherium cuvieri (Fischer). Only the first and third species are abundant (88 and 97 pieces). This two populations are described. The marsupial fauna of the european lower Oligocene is not recognized in its entirety in this site. Article infos Published in Vol. 08, Fasc. 2-4 (1978) |
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Additions to the elasmobranch assemblage from the Bandah Formation (middle Eocene, Bartonian), Jaisalmer District, Rajasthan, India, and the palaeobiogeographic implications of the faunaRajendra S. Rana, Raman Patel, David J. Cicimurri and Jun A. EbersoleKeywords: Chondrichthyes; Elasmobranchii; Indian Ocean; Palaeogene; South Asiadoi: 10.18563/pv.44.2.e1 Abstract Isolated elasmobranch teeth (sharks and rays) from the middle Eocene (Bartonian) Bandah Formation in the Jaisalmer District of Rajasthan, India are described. The remains improve our knowledge of the environment represented by this lithostratigraphic unit and the ecology preserved therein. Seventeen unequivocal taxa were identified, including Nebrius sp., Striatolamia aff. S. macrota, Brachycarcharias atlasi, B. lerichei, cf. Jaekelotodus sp., Carcharhinus mancinae, Rhizoprionodon sp., Physogaleus sp., Galeocerdo clarkensis, G. eaglesomei, Odontorhytis aff. O. pappenheimi, “Rhinobatos” sp., “Dasyatis” sp., Coupatezia sp., “Aetomylaeus” sp., “Rhinoptera” sp., and Ouledia aff. O. lacuna. Of these, “Aetomylaeus” sp., B. atlasi, C. mancinae, G. clarkensis, G. eaglesomei, cf. Jaekelotodus sp., Nebrius sp., Odontorhytis aff. O. pappenheimi, Ouledia aff. O. lacuna, and “Rhinoptera” sp. are reported from the middle Eocene of India for the first time. The Bandah Formation elasmobranch palaeofauna has close affinities to the Palaeocene-Eocene Tethyan/Paratethyan faunas of Africa, Madagascar, Asia, and Europe, and some taxa indicate a western hemisphere influence from North America. The Bandah Formation palaeofauna indicates that deposition occurred in a moderately shallow marine environment. The Bartonian age is primarily based on foraminifera but is corroborated by the presence of elasmobranch taxa that also occur in contemporaneous deposits elsewhere. The marine regression started during the early Palaeogene, and our study indicates that the sea completely withdrew from the Jaisalmer Basin after the deposition of the Bandah Formation. This event may have been synchronous with the middle Eocene uplift of the Himalayan-Tibetan Plateau. Article infos Published in 44-2 (2021) |
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Latest Early-early Middle Eocene deposits of Algeria (Glib Zegdou, HGL50), yield the richest and most diverse fauna of amphibians and squamate reptiles from the Palaeogene of AfricaJean-Claude Rage, Mohamed Adaci, Mustapha Bensalah, Mahammed Mahboubi, Laurent Marivaux, Fateh Mebrouk and Rodolphe TabuceKeywords: Africa; Algeria; amphibians; Eocene; squamatesdoi: 10.18563/pv.44.1.e1 Abstract HGL50 is a latest Early-early Middle Eocene vertebrate-bearing locality located in Western Algeria. It has produced the richest and most diverse fauna of amphibians and squamate reptiles reported from the Palaeogene of Africa. Moreover, it is one of the rare faunas including amphibians and squamates known from the period of isolation of Africa. The assemblage comprises 17 to 20 taxa (one gymnophionan, one probable caudate, three to six anurans, seven ‘lizards’, and five snakes). Two new taxa were recovered: the anuran Rocekophryne ornata gen. et sp. nov. and the snake Afrotortrix draaensis gen. et sp. nov. The locality has also yielded the first confirmed anilioid snake, the first Palaeogene gymnophionan, and probably the first caudate from the Palaeogene (and possibly from the Tertiary) of Africa. The presence of a caudate at that time in Africa would be of particular interest; unfortunately, the available material does not permit a definitive identification. The fauna comprises Gondwanan and more specifically West Gondwanan vicariants, probably autochthonous groups and a Eurasian immigrant (assuming that the identification of the caudate is accurate). The fauna from HGL50 is clearly distinguished from the few other Eocene assemblages of Africa. However, if this results largely from differences in geological ages, geographic positions of the localities and mainly differences in environments took a part in the composition of the faunas. Article infos Published in 44-1 (2021) |
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Comparative bone histology of rhabdodontid dinosaursEdina ProndvaiKeywords: bone histology-based ontogeny; Mochlodon; Rhabdodon; skeletal maturation; Zalmoxesdoi: 10.18563/pv.38.2.e1 Abstract A comparative bone histological study of the three known genera of the endemic European ornithopod dinosaur family, Rhabdodontidae, is presented here in an ontogenetic context. Investigated specimens were assigned to different ontogenetic stages based exclusively on the histological indicators of osteologic maturation during diametrical bone growth; an entirely size-independent method as opposed to most previous studies. Qualitative comparison of bone histology of corresponding ontogenetic stages and elements among the three valid rhabdodontid genera, Mochlodon, Zalmoxes, and Rhabdodon, revealed some consistent patterns. Genus specific histological differences within Rhabdodontidae are most expressed between Rhabdodon and the Mochlodon-Zalmoxes clade. These indicate a prolonged phase of fast growth and a less constrained cyclicity in the growth dynamics of Rhabdodon, as opposed to the slower and more regulated growth strategy reflected in the bones of Mochlodon and Zalmoxes. These genus specific differences are consistent with the phylogenetic interrelation of the genera and are most probably related to the pronounced differences in body size. However, when compared to other ornithopods, most detected histological features in rhabdodontids do not seem to reliably reflect either phylogenetic relations or body size. A notable common feature of all rhabdodontid genera irrespective of body size is the ontogenetically early onset of cyclical growth and secondary remodelling; a pattern that more resembles the condition found in derived ornithopods than that described in more basal taxa which are closer relatives of rhabdodontids. The recognition of taxon-specific histological patterns as well as patterns indicative of ecological and thereby functional traits clearly requires more accurate, preferably quantitative evaluations. Article infos Published in Vol.38-2 (2014) |
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Lower Paleogene crocodilians from Silveirinha, Portugal.Miguel T. AntunesKeywords: ?Upper Paleocene / Lowermost Eocene; Crocodilians; Ecology; PortugalAbstract The presence at Silveirinha of one of the earliest, ? Late Paleocene or Lowermost Eocene, european representatives of the genus Diplocynodon is based mostly on isolated bones and teeth (often from juveniles). This small-sized form is the only crocodilian so far recognized in this site. The longevity of Diplocynodon in Portugal becomes much extended; the genus survived there until the Middle Miocene at least. A discussion on the possible affinities with other eocene Díplocynodon and especially those from Cubillos-Valdegallina (Zamora, Spain) is presented. On the other hand, differences have been detected in comparison with: Díplocynodon tormis, from the middle Eocene of the Douro basin in Spain, which may belong to another phyletic line; and the aff. Diplocynodon from Dormaal (Belgium) and Le Quesnoy (France), nearly contemporaneous of Silveirinha. The Silveirinha Diplocynodon and many other data strongly suggest moist, subtropical, quite limited in space environments related to an alluvial plain crossed by small, meandering channels. Article infos Published in Vol. 32, Fasc. 1 (2003) |
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