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In this paper, we report on abundant fossils of Platybelodon from the Middle Miocene of the Linxia Basin, China. Most of the fossils were discovered at two localities (Laogou and Zengjia) in the upper Middle Miocene Hujialiang Formation, and possess derived characters for the genus, including a relatively slender upper incisor, the development of a transverse ledge on the narrowest part of the mandibular symphysis, narrow, elongate and hypsodont third molars, the development of fourth loph(id)s on the second molars, and the development of small enamel conules and cementum in the interloph(id)s. Following comparisons with other Eurasian platybelodonts, we assign these remains to Platybelodon grangeri, and demonstrate that they are morphologically intermediate between P. grangeri from the Tunggurian localities of Tarim Nor and Platybelodon Quarry in Inner Mongolia. We suggest that the locality of Laogou may be younger than that of Zengjia, based on the occurrence of platybelodonts showing a suite of more derived characters. In addition, we assign two further specimens of Platybelodon from the lower Middle Miocene Dongxiang Formation of the Linxia Basin to Platybelodon danovi, owing to their retention of plesiomorphic characters distinguishing them from other Linxia Platybelodon fossils. Based on a cladistic analysis, we propose an evolutionary sequence of platybelodonts in Eurasia, and discuss potential functional adaptations.
Two species of chinchillid rodents, Lagostomus (Lagostomopsis) incisus and “Lagostomus (Lagostomopsis) spicatus”, have been recorded from the Monte Hermoso Formation (Montehermosan—Lower Chapadmalalan, Early Pliocene) of southern Buenos Aires Province, eastern Argentina. L. (L.) incisus is based on skull remains, while “L. (L.) spicatus” is based on mandible remains and fragmentary skulls. Detailed study of specimens recovered from the upper section of the Monte Hermoso Formation, from the Irene “Formation”, and the Chapadmalal Formation (late Early—early Late Pliocene, Buenos Aires Province), some of them represented by associated skull and mandible remains, indicates that L. (L.) incisus and “L. (L.) spicatus” are synonymous, with the valid name being L. (L.) incisus. The differences between both nominal species are here attributed to different ontogenetic states and sexual dimorphism. The stratigraphic provenance of the fossil material of L. (L.) incisus indicates a temporal distribution of this species restricted to the Montehermosan?—Chapadmalalan (Early—early Late Pliocene), instead of the Montehermosan (Early Pliocene).
We describe and re-evaluate the systematics of specimens from the Maastrichtian Moreno Formation of California (western USA) as a new species of Saurolophus, the only known genus of hadrosaurid dinosaur widespread in Asia and North America. Recognition of this new species adds substantially to the record of the taxonomic diversity of these animals west of the Rocky Mountains. The new species, Saurolophus morrisi, is diagnosed by the possession of a postorbital having ornamentation in form of wide oblique groove on jugal process. Placement of this new species in Saurolophus considerably expands the distribution of this genus, although this referral is arbitrary since phylogenetic analysis places the new species outside of the clade formed by Saurolophus osborni and Saurolophus angustirostris. However, recognition of a new, endemic Californian hadrosaurid, especially one so closely related to both Asian and North American species, may have implications for future studies of both the internal biogeography of Western North America, and the history of exchange with Asia.
The dinosaur record of the Salitral Moreno locality (Río Negro Province, Argentina) is characterized by a high diversity of herbivore taxa, among them hadrosaurs, ankylosaurs, and titanosaur sauropods, but carnivores are rare, consisting of only a few fragmentary bones of small forms. Titanosaurs are represented by Rocasaurus muniozi and Aeolosaurus sp., and at least four other taxa, represented by fragmentary material. The elements preserved include a cervical, dorsal and caudal vertebrae, chevron, humerii, ulnae, radii, metacarpal, femora, tibiae, metatarsal, ischia, pubis, and ilium. The Allen Formation is thought to be correlated with the Marília Formation in Brazil, and their faunas have certain elements in common such as aeolosaurines, but saltasaurines and hadrosaurs, are known exclusively from the Allen Formation. These absences, and particularly that of the saltasaurines, may be because those sauropods originated late in the Cretaceous, probably in southern South America (Northern Patagonia?), and they did not have time to disperse to northern South America.
A specimen of slender skulled monofenestratan pterosaur from the Upper Jurassic Kimmeridge Clay Formation of Dorset, UK, is referred to the new genus and species Cuspicephalus scarfi. The dentition and posterior skull morphology suggest affinities with Darwinopterus, but a close relationship cannot be proved. There are also some similarities with the pterodactyloid Germanodactylus cristatus, but the presence of teeth on the distal rostrum excludes it from that genus. Pterosaur remains are rare in the Upper Jurassic of the UK and this specimen represents the first significant cranial remains of a pterosaur from the Kimmeridge Clay Formation, and possibly the first non-pterodactyloid monofenestratan outside China.
A new albanerpetontid, Wesserpeton evansae gen. et sp. nov., from the Early Cretaceous (Barremian) Wessex Formation of the Isle of Wight, southern England, is described. Wesserpeton is established on the basis of a unique combination of primitive and derived characters relating to the frontals and jaws which render it distinct from currently recognized albanerpetontid genera: Albanerpeton (Late Cretaceous to Pliocene of Europe, Early Cretaceous to Paleocene of North America and Late Cretaceous of Asia); Celtedens (Late Jurassic to Early Cretaceous of Europe); and Anoualerpeton (Middle Jurassic of Europe and Early Cretaceous of North Africa). Although Wesserpeton exhibits considerable intraspecific variation in characters pertaining to the jaws and, to a lesser extent, frontals, the new taxon differs from Celtedens in the shape of the internasal process and gross morphology of the frontals in dorsal or ventral view. It differs from Anoualerpeton in the lack of pronounced heterodonty of dentary and maxillary teeth; and in the more medial location and direction of opening of the suprapalatal pit. The new taxon cannot be referred to Albanerpeton on the basis of the morphology of the frontals. Wesserpeton currently represents the youngest record of Albanerpetontidae in Britain.
A new fossil spider from the Triassic (Norian) Dolomia di Forni Formation of Friuli, Italy, is described as Friularachne rigoi gen. et sp. nov. This find brings the number of known Triassic spider species to four. The specimen is an adult male, and consideration of various features, including enlarged, porrect chelicerae, subequal leg length, and presence of a dorsal scutum, point to its identity as a possible member of the mygalomorph superfamily Atypoidea. If correct, this would extend the geological record of the superfamily some 98–115 Ma from the late Early Cretaceous (?Albian, c. 100–112 Ma) to the late middle-early late Norian (c. 210–215 Ma).
Termites of the family Stolotermitidae are a relict lineage of primitive Isoptera. The fossil record of Stolotermitidae is exceptionally poor, with only two Miocene (Neogene) species documented to date. Herein, a new genus and species of Paleogene termites is described and figured from the Late Oligocene (28-27 Ma, Early Chattian) of northwestern Ethiopia (Amhara Region, Chilga Woreda). Chilgatermes diamatensis gen. et sp. nov., is most similar to genera of the Stolotermitidae, Archotermopsidae, and Termopsidae but can be distinguished on the basis of forewing venational details. The genus is tentatively placed in the Stolotermitidae: Porotermitinae. Chilgatermes diamatensis is the first fossil termite from Ethiopia and, indeed, the first from the entire African continent.
Decapod crustaceans are the most diverse group of fossil invertebrates from the Upper Cretaceous Sahel Alma Lagerstätte (Lebanon, Middle East). They are mainly represented by abundant crest-bearing shrimps which were first described as Penaeus libanensis. We review this species applying the new systematic nomenclature and we propose a more complete description based on 54 unpublished specimens. This review leads to the erection of Palaeobenthesicymus gen. nov. and to the new combination Palaeobenthesicymus libanensis that is the oldest record of the family Benthesicymidae. A neotype is herein designated. Detailed comparisons with extant analogues suggest that the crest bearing shrimps inhabited relatively deep water settings most probably exceeding 150 m, at the transition between the lower circalittoral and the upper bathyal zones, under dysphotic or aphotic conditions.
Clusters of gastropod egg capsules, inferred to be of neritoids and attached to the inner shell wall of the ultimate whorl of a large volutid gastropod, are here recorded from the upper Nekum Member (Maastricht Formation; late Maastrichtian) of the ENCI-Heidelberg Cement Group quarry, St Pietersberg (Maastricht, southeast Netherlands). Because the aragonitic shell of the volutid has dissolved, the outlines of the egg capsules are now revealed on the steinkern of indurated biocalcarenite, having been subsequently overgrown by cheilostome bryozoan colonies and preserved as mould bioimmurations. This represents the first example of gastropod eggs preserved through bioimmuration, as well as the first record of gastropod eggs from the Cretaceous.
Exceptionally well preserved specimens of the bivalve mollusc Modiola major were collected from a Lower Cretaceous (Barremian) hydrocarbon seep deposit in northern California. This material, together with the type series of M. major, and various other specimens from Upper Jurassic to Lower Cretaceous seep localities in California, is redescribed and referred to the hydrocarbon seep-restricted modiomorphid genus Caspiconcha. We include also a description of Myoconcha americana because some previous reports have incorrectly synonymized Myoconcha americana with Caspiconcha major. In addition, we report Caspiconcha sp. from a Lower Cretaceous (Albian) hydrocarbon seep from Hokkaido, Japan, and we review all currently described species of Caspiconcha, and other species that probably belong to this genus. We demonstrate that Caspiconcha had a widespread distribution in Late Jurassic to Early Cretaceous hydrocarbon seeps, but became rare thereafter, with the last representative occurring in Upper Cretaceous strata of Japan. This macroevolutionary pattern is similar to that observed in the seep-restricted brachiopods. After the decline of Caspiconcha at the end of the Early Cretaceous and its last occurrence in the Campanian, the ecological niche of epifaunal to semi-infaunal seep endemic bivalves was largely vacant and not reoccupied until the Eocene with the appearance of the vesicomyid and bathymodiolin bivalves. The formal placement of M. major into the genus Caspiconcha restricts the fossil record of mytilids at seeps to post-Mesozoic times, and thus there is less discrepancy between the fossil record of chemosynthetic mytilids and their divergence age estimates from molecular data.
Spines are one of the most characteristic ornamenting features of many fossil brachiopod taxa. Despite several studies of spines in different species, there is still insufficient information about the development, functional morphology, and modifications of brachiopod spines. In particular, ontogenetic data are very rare and the understanding of the relationship between functional morphology and paleoecology is elusive. The present study analyzes the functional morphology and modifications on spines of the Pennsylvanian brachiopod species Heteralosia slocomi throughout ontogeny. Spines are tubular hollow and only displayed on the surface of the ventral valves, where they develop from a specific point at the margins of the growth lamellae and directed towards the antero-lateral margins. Modifications of up to 180° from this original direction of growth are observed in response to ecological pressure and biotic interactions. The function of these spines is primarily for attachment by clasping and cementation, but the possibility of spines acting as sensory mechanisms is not excluded.
The Late Triassic was a time of pronounced radiation in several groups of foraminifers. The rapid evolutionary processes in the Suborder Involutinina caused particularly high diversification of these aragonitic foraminifers, which became a key group for Upper Triassic biostratigraphy. Among them, Triasina hantkeni and Triasina oberhauseri are regarded as the most precise guide fossils. However, while these species are widely used, a poor documentation of the detailed test structure of T. oberhauseri has resulted in misidentifications. The exceptional preservation and abundance of Triasina oberhauseri in the Upper Triassic deposits of the Black Marble Quarry (Wallowa terrane, Oregon, USA) has allowed us to make the first detailed observations of its coiling, innermost structure and lamellae arrangement and to recognize morphological features that were either wrongly interpreted or not described in the original systematic definition of the species. In this paper, we demonstrate that the species possesses characteristics that hamper its assignment to Triasina and we propose a new genus, Aulosina, to accommodate this taxon. Placing emphasis on the accuracy of the morphological description, the diagnosis and the systematic definition of the species are here improved. The identification of innovative features in Aulosina oberhauseri (strengthenings, shortened lamellae) highlights new evolutionary trends for the lineage of Involutinina that have proved useful for the establishment of phylogenetic links between involutinid genera and for understanding the evolutive steps leading to the formation of inner-pillars in tubular foraminifers. The increasing complexity of Involutinina representatives at the end of the Triassic, notably marked by the appearance of internal structures in Triasininae, leads us to regard them as probable symbiont-bearing foraminifers.
Latest Cretaceous (Campanian to Maastrichtian) leaf fossil assemblages are described from 33 exposures ranging from the southern border of the Holy Cross Mountains (southern Poland) through the Roztocze region (south-eastern Poland) to the vicinity of L'viv (western Ukraine). The fossil assemblage is allochthonous, preserved in marine sediments, yet complete compound leaves strongly argue for the transport having been short. Krasnobród and Potelych (Potylicz) are the richest localities; both are late Campanian. The abundance of angiosperm remains in this period is explained by a marine lowstand resulting in nearby emergent vegetated areas. The flora was composed of ferns (three species), conifers (five species, including the commonest Geinitzia reichenbachii), dicotyledons (seventeen taxa; Debeyapaulinae sp. nov., two other species of Debeya, and Rarytkinia polonica being the most frequent), and a single presumed monocotyledon. The eudicot clade is formalised as supersubclass Eudicotyledoneae Doyle and Hotton ex Halamski, herein. The approximately equal abundance of serrate/lob ate and entire-margined dicots attests to an intermediate character of the flora between more thermophilic and polar vegetation. The material may have come from at least two communities: xeromorphic mixed Debeya-coniier forests and platanoid-Lauraceae forests growing in disturbed environments along rivers. The assemblage is most similar to approximately coeval floras from Westphalia and the Netherlands.
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