| 1. |
- Blom, Henning, et al.
(författare)
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Devonian vertebrates from East Greenland : a review of faunal composition and distribution
- 2007
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Ingår i: Geodiversitas. - 1280-9659 .- 1638-9395. ; 29:1, s. 119-141
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Forskningsöversikt (refereegranskat)abstract
- The Devonian vertebrate faunas of East Greenland are reviewed and their distribution discussed for the first time in the light of the most recently published stratigraphical framework for the area. The predominantly Middle and Upper Devonian continental sediments have yielded representatives of most major groups of early fossil vertebrates, including heterostracans, placoderms, acanthodians, chondrichthyans, actinopterygians, lungfishes, porolepiforms, "osteolepiforms" and tetrapods, but to date, no single publication has treated them all in their stratigraphical context. We therefore attempt to place them into the most recent, formalised lithostratigraphy, providing improved resolution for their stratigraphical distribution, as a basis for comparing East Greenland with other Devonian faunal successions worldwide. The review highlights the fact that many problems of stratigraphical correlation and dating of the East Greenland Devonian deposits remain to be resolved by further fieldwork. Several assemblages ranging from Givetian to Famennian in age can be distinguished, that correspond to older superceded subdivisional nomenclature. A possible Frasnian fauna has been recognised for the first time, adding details to an otherwise poorly dated part of the succession. Typical Devonian taxa such as Holoptychius Agassiz, 1839 and Groenlandaspis Heintz, 1932 have apparently been recorded in an otherwise unique position above the Devonian-Carboniferous boundary in the upper part of the succession. New specimens of rare elements of the fauna including an unknown arthrodire placoderm, a putative chondrichthyan spine and a patch of possibly regurgitated acanthodian spines, are illustrated for the first time.
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| 2. |
- Dupret, Vincent, 1977-
(författare)
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Revision of the genus Kujdanowiaspis Stensiö, 1942 (Placodermi, Arthrodira, "Actinolepida") from the Lower Devonian of Podolia (Ukraine)
- 2010
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Ingår i: Geodiversitas. - : Museum National d'Histoire Naturelle, Paris, France. - 1280-9659 .- 1638-9395. ; 32, s. 5-63
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Tidskriftsartikel (refereegranskat)abstract
- The genus Kujdanowiaspis Stensiö, 1942 has long been considered as the archetype of placoderms; hence, it has been often used as outgroup in phylogenetic analyses involving placoderms, or used as a representative of all the placoderms for all early vertebrate works. Nevertheless, there has been no real work on the taxonomy of this genus since Denison (1978). Here we propose a revision of the material of Kujdanowiaspis from the Old Red Sandstone of Podolia (including neurocrania, skull roofs and thoracic armours), together with the description of unpublished specimens of the genus Heightingtonaspis White, 1969. Among the available Podolian material, three species are considered valid: Kujdanowiaspis buczacziensis (Brotzen, 1934), K. podolica (Brotzen, 1934) and Erikaspis zychi (Stensiö, 1945) (K. podolica and K. buczacziensis only differ in size and in the density and size of the tuberculated ornamentation; the dermal plate pattern of E. zychi differs from that of the genus Kujdanowiaspis). The axillar area of the scapulocoracoid of K. podolica is compared with those of an osteostracan “agnathan” and of a non-tetrapod sarcopterygian. In the three cases, the articulation of the pectoral fin is of the monobasal type. An analogy with the embryonic development of the pectoral fin of the actinopterygian Danio rerio (Hamilton, 1822) suggests that the monobasal articulation would correspond to the plesiomorphic condition compared with the multibasal one of the adult actinopterygians and some derived brachythoracid placoderms. The suprasynarcual is a newly identified, chondrified element of the vertebral column, supposed to respond to the height of the median dorsal plate in Kujdanowiaspis podolica.
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| 3. |
- Miguel Sender, Luis, et al.
(författare)
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A new uppermost Albian flora from Teruel province, northeastern Spain
- 2012
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Ingår i: Geodiversitas. - : Museum National d'Histoire Naturelle, Paris, France. - 1638-9395 .- 1280-9659. ; 34:2, s. 373-397
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports a new Early Cretaceous flora discovered recently near the village of Estercuel (Teruel province, northeastern Spain). The plant bearing beds belong to the uppermost part of the Early Cretaceous succession, at the top of the fluvial deposits of the Utrillas Formation. The site has yielded a diverse assemblage of plant compressions including lycopods and ferns, various gymnosperms as well as terrestrial and aquatic angiosperms. Leaves of aquatic lycopods (Isoetites sp.) constitute a minor component of the palaeobotanical assemblage. Filicales are not very common, with Dicksoniales (Onychiopsis sp.) and a few specimens of Cladophlebis type fronds. The gymnosperms are represented by fragmented remains of long parallel veined Desmiophyllum leaves as well as a great abundance of conifer axis corresponding to the form-genus Pagiophyllum and female cones. Terrestrial angiosperms include pinnately lobed leaves of the genus Myricompia, simple leaves with spatulate lamina and some petiolate leaves both corresponding to angiosperms of uncertain affinity. Aquatic angiosperms consist of Nelumbo-like floral receptacles (Nelumbonaceae, Proteales) and Aquatifolia cf: fluitans (Nympheales). The palynological assemblage is dominated by pollen of gymnosperms (mainly Taxodiaceaepollenites hiatus, Classopollis major and Araucariacites australis). It also includes many angiosperm grains (Afropollis jardinus, Clavatipollenites spp., Di-chastopollenites spp., Liliacidites doylei, Monosulcites chaloneri, Penetetrapites mollis, Pennipollis spp., Phimopollenites augathellaensis, Retimonocolpites textus, Rousea spp., Senectotetradites varireticulatus, Stellatopollis barghoornii, Striatopollis spp., Transitoripollis sp. cf. T similis, Tricolpites spp., Tricolporoidites sp.) and records the first occurrence of tricolporate forms in the uppermost part of the Utrillas Formation. Both macroflora and microflora assemblages present taxa similar to those of the uppermost Albian Shaftesbury Formation in northwestern Alberta in Canada, the uppermost Albian Denton Shale Member of Bokchito Formation in southern Oklahoma, the lower part of the Upper Albian Dakota Formation from the mid-west of North America, and Subzone II C of the Potomac Group, eastern United States. Both macro- and microflora assemblages display boreal influence with some similar taxa to those of the Upper Albian Kome Formation in western Greenland and some taxa as Afropollis jardinus and Stellatopollis barghoornii more frequently found in the tethyan and gondwanan realms. A gondwanan affinity is also indicated by the presence of Klitzschophyllites leaves.
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| 4. |
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| 5. |
- Van Laere, Gaëlle, et al.
(författare)
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Beavers and flying squirrels (Rodentia: Castoridae, Pteromyini) from the Late Pliocene of Hambach 11C, Germany
- 2023
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Ingår i: Geodiversitas. - 1280-9659 .- 1638-9395. ; 45:7, s. 223-241
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Tidskriftsartikel (refereegranskat)abstract
- This paper is a study of part of the rodent fauna collected at Hambach 11C, located in the Hambach lignite mine in north-western Germany. The deposits exposed here are fluvial channel fills of Late Pliocene age (MN16a) and the rodent material is compared to previously published material from the contemporaneous deposits of Hambach 11. Four species are discussed: two Castoridae, Castor fiber Linnaeus, 1758 and Trogontherium minus Newton, 1890 and two Sciuridae, Blackia miocaenica Mein, 1970 and Pliopetaurista pliocaenica Depéret, 1897. This new material is of great importance as the fossil records of T. minus and B. miocaenica are very scarce so far. Blackia is especially rare in the Late Pliocene and this occurrence is one of the three youngest of the genus. We also described the most complete juvenile material of Trogontherium minus. The fauna is indicative of fluvial environment surrounded by a forest of deciduous trees and of a temperate and humid climate.
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| 6. |
- Werdelin, Lars
(författare)
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Middle Miocene Carnivora and Hyaenodonta from Fort Ternan, western Kenya
- 2019
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Ingår i: Geodiversitas. - : Museum National d'Histoire Naturelle, Paris, France. - 1280-9659 .- 1638-9395. ; 41:6
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Tidskriftsartikel (refereegranskat)abstract
- Fort Ternan is a middle Miocene (c. 13.7-13.8 Ma) site famous for its fossils of Kenyapithecus wickeri Leakey, 1962, considered the earliest African hominoid. Herein, the Carnivora and Hyaenodonta from this site are described and placed in their temporal context, showing the middle Miocene to be a time of transition from archaic carnivores of the early Miocene and carnivores of more modern aspect from the late Miocene. Fort Ternan includes: Amphicyonidae represented by ?Myacyon peignei n. sp., a new form distinguished by its hypercarnivorous m1, P4 with large protocone shelf, and M1 with reduced lingual shelf; Barbourofelidae, represented by a derived form; Percrocutidae, represented by abundant material of Percrocuta tobieni Crusafont & Aguirre, 1971; Viverridae, represented by the paradoxurines Kanuites lewisae Dehghani & Werdelin, 2008, and cf. Orangictis Morales & Pickford, 2005, and a putative viverrine; and Hyaenodonta represented by the teratodontine Dissopsalis pyroclasticus Savage, 1965 and a very large hyainailourine. This assemblage is a melange of forms harkening back to the early Miocene (the Hyaenodonta and Amphicyonidae), an evolving, still extant lineage (Viverridae), and more typical late Miocene forms (derived Barbourofelidae and Percrocutidae).
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| 7. |
- Werdelin, Lars, et al.
(författare)
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The last amphicyonid in Africa
- 2009
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Ingår i: Geodiversitas. - 1280-9659 .- 1638-9395. ; 31, s. 775-787
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Tidskriftsartikel (refereegranskat)abstract
- Amphicyonidae are a common element of carnivoran faunas in the early and middle Miocene of Eurasia and North America, but by the Messinian they had become extinct there, except possibly on the Indian subcontinent. In Africa, amphicyonids are poorly known from a scattering of records from the late Oligocene to the late Miocene. In this paper, we describe the last-surviving amphicyonid in Africa, from Messinian-age sediments (dated c. 6.5-5.3 Ma) of Ethiopia (Gona) and Kenya (Lothagam and possibly Lemudong’o). Th is new taxon shows unique adaptations to hypercarnivory in the lower molars and was small for an amphicyonid, dentally about the size of a coyote, Canis latrans.
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| 8. |
- Zigaite, Zivile, et al.
(författare)
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New observations on the squamation patterns of articulated specimens of Loganellia scotica (Traquair, 1898) (Vertebrata : Thelodonti) from the Lower Silurian of Scotland
- 2012
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Ingår i: Geodiversitas. - : Museum National d'Histoire Naturelle, Paris, France. - 1280-9659 .- 1638-9395. ; 34:2, s. 253-270
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Tidskriftsartikel (refereegranskat)abstract
- Articulated squamations of Loganellia scotica (Traquair, 1898) from the Lower Silurian Lesmahagow inliers of southern Scotland have been studied. They include seven articulated specimens, three of them representing complete thelodont fossils, and four partially preserved postpectoral, precaudal and caudal parrs of the exoskeleton. All the five main types of thelodont scales that is rostral, cephalo-pectoral, postpectoral, precaudal and pinnal sacles, as well as respective squamation patterns have been observed on articulated specimens. The specific orbital, branchial, and bucco-pharyngeal scales, characteristic of L. scotica, have not been found due to the poor or non-preservation of these particular areas within the specimens studied. Tail morphology and squamation pattern of the caudal fin have been studied with particular attention, and the constitution of the caudal fin rays has been analyzed. The rostral squamation pattern is argued to be characteristic to L. scotico.
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| 9. |
- Mora-Rojas, L., et al.
(författare)
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Stratigraphy of a middle Miocene neotropical Lagerstatte (La Venta Site, Colombia)
- 2023
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Ingår i: Geodiversitas. - 1280-9659. ; 45:6, s. 197-221
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Tidskriftsartikel (refereegranskat)abstract
- The middle Miocene Konzentrat-Lagerstatte of the La Venta site recorded in the Honda Group contains invaluable information on the biotic response to the climatic changes of the Miocene Climatic Transition. Its fossil record has been studied for almost a century and offers one of the best windows to the Neotropics terrestrial ecosystems during the Neogene. We have compiled all published studies and, using graphic correlation and a recently published geological map for the region, placed them into a composite standard section. Furthermore, we improved its chronostratigraphic control by analyzing new geochronological data (U-Pb in zircons) and developing a probabilistic age model using a Bayesian framework. The results suggest that most of the fossil assemblage of the Honda Group accumulated in a meandriform fluvial system (upper part of La Victoria Formation - lower part of Villavieja Formation) that later shifted to an anastomosed system (upper part of Villavieja Formation). The c. 552-m-thick La Victoria Formation is younger than 16 Ma and older than 12.58 Ma, whereas the c. 569-m-thick Villavieja Formation is younger than 12.58 Ma and older than 10.52 Ma. The La Venta site is crucial for understanding Miocene paleoecological dynamics in northern South America, but despite decades of studies, it is still in the early phase of exploration.
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