Burmese amber is an extremely important source of mid-Cretaceous plant and animal remains with over 870 species of organisms, ranging from protozoa to vertebrates, described from this source. The amber mines are located on the West Burma Block that according to geologists was originally part of Gondwana. The present study introduces some angiosperms and insects in Burmese amber whose closest extant relatives have a Gondwanan distribution and there is no previous evidence of a Laurasian distribution. Based on this evidence, it is proposed that organisms in Burmese amber represent a selection of tropical to subtropical life forms that inhabited the interconnected continents of Gondwana in the Early Cretaceous. Based on the fossil record of angiosperms and their diversity in Burmese amber, the West Burma Block could not have rafted from Gondwana to SE Asia before the Early Cretaceous.
The Val Gardena Formation of the Dolomites region in northern Italy preserves the most significant assemblage of Late Permian tetrapod footprints in the world. More than 120 years of collecting resulted in about 900 publicly accessible specimens from the study area. This huge amount of data is comprehensively revised in the light of recent advances in the study of Late Palaeozoic - Early Mesozoic tetrapod ichnofossils. According to our analyses, the Val Gardena Sandstone Formation includes tracks that can be assigned to cf. Batrachichnus isp. (temnospondyl amphibian), Capitosauroides isp. (amphibian), Dicynodontipus isp. (cynodont therapsid), Dolomitipes accordii n. igen. n. comb. (dicynodont therapsid), cf. Dromopus isp. (neodiapsid), Pachypes dolomiticus (pareiasaurian parareptile), Paradoxichnium problematicum (archosauromorph neodiapsid), Procolophonichnium tirolensis n. comb. (procolophonoid parareptile), cf. Protochirotherium isp. (archosauriform neodiapsid) and Rhynchosauroides pallinii (neodiapsid). The ichnoassociation is dominated by tracks of neodiapsid and parareptilian tetrapods, whereas synapsid and anamniote tracks are rather minor components. It includes 10 out of 12 tetrapod ichnogenera known from Lopingian deposits and thus it constitutes a reference for the Paradoxichnium biochron. It shows striking similarities with other low-latitude non-aeolian contemporaneous ichnoassociations of Europe and North Africa, differences may be linked to the palaeoenvironment. Moreover, it shows a clear Triassic affinity. The new ichnogenus Dolomitipes was registered in Zoobank.org. urn:lsid:zoobank.org:act:5B4D871C-D16A-4E93-8211-CEE08019BA60
The Cave Bear, Ursus spelaeus (sensu lato), was one of many megafaunal species that became extinct during the Late Pleistocene in Europe. With new data we revisit the debate about the extinction and paleoecology of this species by presenting new chronometric, isotopic and taphonomic evidence from two Palaeolithic cave bear sites in northeastern Italy: Paina Cave and Trene Cave. Two direct radiocarbon dates on well-preserved collagen have yielded ages around 24,200-23,500 cal yr BP, which make them the latest known representatives of the species in Europe. The carbon (δ 13 C) and nitrogen (δ 15 N) isotopic values of bone collagen exhibit values similar to those of older cave bears from Swabian Jura and France, suggesting that the feedings preferences of cave bears remained unchanged until the disappearance of this species in Europe. Several bear remains preserved traces of human modification such as cut marks, which enables a reconstruction of the main steps of fur recovery and the butchering process. The broad range of plant types available and the favorable location of Berici Hills may have played an important role in the range expansion of cave bears and their interaction with the Paleolithic hunters settled the same area.
Here we report the first record of one of the most common and widespread Palaeogene selachians, the sand tiger shark Brachycarcharias, from the Ypresian Bolca Konservat-Lagerstätte. The combination of dental character of the 15 isolated teeth collected from the Pesciara and Monte Postale sites (e.g. anterior teeth up to 25 mm with fairly low triangular cusp decreasing regularly in width; one to two pairs of well-developed lateral cusplets; root with broadly separated lobes; upper teeth with a cusp bent distally) supports their assignment to the odontaspidid Brachycarcharias lerichei (Casier, 1946), a species widely spread across the North Hemisphere during the early Palaeogene. The unambiguous first report of this lamniform shark in the Eocene Bolca Konservat-Lagerstätte improves our knowledge concerning the diversity and palaeobiology of the cartilaginous fishes of this palaeontological site, and provides new insights about the biotic turnovers that involved the high trophic levels of the marine settings after the end-Cretaceous extinction.
More than 300 cave bear bones from all over Europe have carbon and nitrogen isotopic composition that match overwhelmingly a diet based on plants, except for samples from two caves in Romania, for which high nitrogen-15 amounts have been interpreted as reflecting an omnivorous diet. This paper aims at deciphering the various factors influencing the carbon and nitrogen isotopic composition of a potential omnivorous species like cave bear, those linked to trophic levels and variations among plants and those caused by physiological factors. The comparison of European cave bears with coeval Late Pleistocene large mammals with different diets clearly shows that all the cave bear populations, including those from Romania, present isotopic values overlapping with herbivores, not with carnivores. Therefore omnivory is very unlikely for cave bears. Consumption of plants with high δ 15 N values, such as graminoids, forbs and possibly fungi, could explain in part the observed isotopic pattern. In addition, the variations in δ 15 N values through ontogeny support the hypothesis of a different hibernation pattern for the Romanian cave bears with high δ 15 N values. Future investigations using new isotopic approaches, especially nitrogen isotopic composition of collagen amino acids, should contribute to decipher the paleoecology of these Romanian cave bears.
The first fossil anguine material from the lower Miocene (MN 2) locality Ulm - Westtangente in Germany is described. The parietal and compound bone of the lower jaw can be attributed to Ophisaurus holeci, previously known only from younger age (MN 3-MN 7). Moreover, the parietal represents the largest parietal of this species. In other disarticulated material, such as frontal, maxilla, dentary and osteoderms, alpha taxonomy is not possible and these elements cannot be allocated at the species level. Despite a limited data source, a phylogenetic analysis was done (16 taxa, 36 characters) producing four equally parsimonious trees. The analysis shows a close relationship of O. holeci and the Eocene Ophisauriscus quadrupes. These two taxa form a monophyletic clade, a sister-clade to Ophisaurus + Anguis. However, more complete skeletal material of O. holeci is needed to support such a statement. We used our phylogenetic analysis to analyze trace character history for one frontal and three parietal characters. The palaeoenvironmental conditions of the locality Ulm - Westtangente bring further support of the previous hypothesis that O. holeci was adapted to environments with high ground water levels - environments around lakes or rivers.
Only recently, new ontogenetic series of early dinosaurs and related groups have been described. Here, we present an isolated immature dinosauriform femur from the Late Triassic of southern Brazil and investigate its influence on character polarization. Because the specimen shares a number of synapomorphies with Pampadromaeus barberenai, herein we postulate that it corresponds to a juvenile individual of that taxon. Accordingly, we investigate the morphological variation between juvenile and mature individuals of P. barberenai. Scoring these character states into a published phylogenetic data-set of Dinosauromorpha reveals that morphological variation is higher than that observed among closely-related taxa. Ontogenetic variation thus exerts influence on character polarization. In addition, modification of the scores affected by ontogeny produces different topologies, as noted by the reduction in both the number of most parsimonious trees and number of steps, and increased inclusivity of some clades and reduction of polytomies as well. Our study, together with other recent contributions, sheds light on the morphologic pathways seen during dinosauromorph ontogenetic development, which is crucial to more reliably assess phylogenetic reconstructions and macroevolutionary patterns of this widespread and successful group.
The rich and relatively diverse fossil mammalian assemblage from Gökler is of special importance for understanding of faunal evolution in Central Anatolia. Large mammals were not recovered, but insectivores and rodents are abundant. The assemblage of rodents is studied in detail and comprises mainly diversified cricetids. Dormice are abundant, but are represented by only one species. Squirrels are represented only by few specimens and also beaver remains were identified. Spanocricetodon sinuosus is referred to a new genus Latocricetodon nov. gen that is tentatively assigned to the Pseudocricetodontinae. Newly named species are Cricetodon goklerensis sp. nov., Democricetodon haltmari sp. nov., Eumyarion lukasi sp. nov. and Glirudinus matusi sp. nov. The rodent assemblage is assigned to local zone C which is correlated to the European biounit MN2 (early Miocene). Our biochronological assessment is supported by radiometric dating from two volcanic ash layers. Latocricetodon LSID http://zoobank.org/urn:lsid:zoobank.org:act:3414DB1E-0C5E-4154-BE5E-02A9ED183B1A Cricetodon goklerensis LSID http://zoobank.org/urn:lsid:zoobank.org:act:1B658872-6C10-4355-B87C-3E6277AF4EDA Democricetodon haltmari LSID http://zoobank.org/urn:lsid:zoobank.org:act:9B13F956-7F8C-406A-9970-1F5E999E54C6 Eumyarion lukasi LSID http://zoobank.org/urn:lsid:zoobank.org:act:34DED87E-855F-4969-AB84-10BED5C572BF Glirudinus matusi LSID http://zoobank.org/urn:lsid:zoobank.org:act:798ECB9A-E3B5-4C38-B5B3-FEB17AF734FE
Silesaurus opolensis Dzik, 2003 from the Late Triassic (late Carnian) of Poland is a key taxon for understanding the evolution of early dinosaurs. High intraspecific variation observed in the S. opolensis braincase brings caution in taxonomic and diversity studies of early dinosauromorphs. The external and internal osteology of three almost complete braincases of S. opolensis show that this taxon shares several similarities with other early dinosauriforms, which supports a close relationship among these forms. However, the paroccipital processes of S. opolensis are directed ventrally like in birds, reaching the level of the ventral margin of the basioccipital condyle. In dinosauromorphs, these processes usually have an almost horizontal orientation (presumed to be the plesiomorphic condition). Modifications observed in birds and S. opolensis have resulted in the dorsoventral expansion of M. complexus and M. depressor mandibulae, which occupy the dorsolateral part of the posterior side of the skull. In adult birds, these muscles act strongly on the initial upstroke of the head during drinking. Therefore, the inferred condition of these muscles in S. opolensis may imply that Silesauridae evolved toward bird-like feeding behaviour.
We here describe new remains of amphibians and reptiles from the early Miocene (MN 4) of two different Greek localities, Aliveri and Karydia. The newly described material consists of urodelans, alytids, indeterminate anurans, turtles, crocodylians, lacertids, indeterminate scincomorphs, anguids, colubrids, viperids, and indeterminate snakes. The presence of the frog Latonia cf. gigantea in Greece is documented for the first time. Additionally, the presence of viperids in Aliveri implies a much wider distribution for these snakes during the early Miocene of Europe. Of special interest is the presence of a peculiar colubrid that seems to possess a hitherto unknown vertebral structure, which is herein defined as the 'paracentral ridge'. Although incomplete, the new material has important taxonomic and biogeographic implications, as it enhances our understanding of southeastern European herpetofaunas from the early Miocene, a time period that was characterised by major dispersal and extinction events and climatic change that affected the whole continent.
The Stegosauria represents an iconic group of ornithischian dinosaurs, with a fossil record spanning the Middle Jurassic to the Late Cretaceous. In this contribution I present the first detailed analysis of the relationship between disparity and diversity through the evolutionary history of the group. The analysis has been performed on a recently published cladistic dataset, allowing the separate study of the signals deriving from discrete characters and from continuous morphometric characters. Whereas the disparity as sum of variance is decoupled with respect to diversity, the sum of ranges provides a signal fairly consistent with the trend in the number of taxa. Both sub-data sets show that evolution of stegosaurs can be considered essentially as symmetrical, i.e. the maximum exploration of the possible morphospace takes place about half way through the history of the group, with subsequent significant decline until extinction in the Upper Cretaceous. An interesting result is a decoupling of the tempo and mode of evolution of the cranium and postcranium in stegosaurs. Specifically, the evolutionary radiation with maximum saturation of morphospace is anticipated in the cranial skeleton, with maximum peak in the Oxfordian; in contrast, the postcranium explores the largest number of morphotypes subsequently during the Kimmeridgian.
Turtle (Testudines) tracks, Chelonipus torquatus, reported from the early Middle Triassic (Anisian) of Germany, and Chelonipus isp. from the late Early Triassic (Spathian) of Wyoming and Utah, are the oldest fossil evidence of turtles, but have been omitted in recent discussions of turtle origins. These tracks provide significant clues as to how early the turtle Bauplan originated. Turtle trackways are quite distinctive: the manus and pes form tracks nearly parallel to the midline and indicate an unusually wide gait in which the trackway width is nearly equal to the stride length. These tracks do not fit what would be expected to be made by Triassic Pappochelys or Odontochelys, a supposed prototurtle and an early turtle, respectively. In contrast, these tracks are consistent with what would be expected from the Triassic turtles Proganochelys and Palaeochersis. The features inferred to be present in Triassic turtle tracks support the notion that Odontochelys is a derived aquatic branch of the turtle stem lineage rather than the ancestral state of all turtles. Chelonipus also resembles the Permian track Pachypes dolomiticus, generally assigned to a pareiasaur trackmaker. These revelations highlight the need to consider all available evidence regarding turtle origins, rather than just the body fossils.
Two recent studies have independently recovered Pisanosaurus mertii - long thought to represent the oldest known member of Ornithischia - within Silesauridae. These finds are expanded upon here, as are the implications of this hypothesis. Based upon these finds, it now appears that Ornithischia was absent in the Triassic Period entirely, which constitutes a major incongruence between the fossil record and current phylogenetic hypotheses, particularly the traditional model of dinosaur interrelationships in which Ornithischia and Saurischia are sister-taxa. It has been suggested previously that Ornithischia was simply a rare component of Late Triassic faunas, or that perhaps the clade's ecology or geographic distribution were not conducive to producing a fossil record. Here I propose that phylogeny could hold the solution to this problem. I examine how an alternative position for Ornithischia - nested either within Theropoda or Sauropodomorpha - could be the reason behind their later appearance and relative rarity in the Early Jurassic. An Early Jurassic origin of Ornithischia would force us to consider that the anatomical similarities between ornithischians and Early Jurassic taxa might not be convergences, and to broaden the current datasets of early dinosaurs to test these ideas.
Plant fossils are known from the Azores Islands, yet poorly studied. We present a comprehensive bibliographical review for the archipelago. A first pre-scientific reference dates from late fifteenth century, while the first scientific description was reported in 1821, accounting for trunks in pyroclastic units and silicified plants within hydrothermal deposits. Throughout the second-half of the nineteenth century and the first-half of the twentieth century, prospection by naturalists and geological mapping work, led to the discovery and description of plant fossils in most islands. From the 1970s onwards, the taxonomic interest ceased, and plant fossils were used mainly for 14 C dating. Recently, sediment cores from lakes and peatlands were used for palaeoecological reconstructions and to measure anthropogenic impacts. Generally, plant fossils are younger than 50 ka, although older fossils may exist. Azorean plant fossils include somatofossils of leaves, stems, logs and seeds preserved as impressions, compressions, adpressions, permineralizations, lava tree casts and mummifications. The taphonomy of macrofloral elements is usually related to explosive volcanic activity, while palynological record is associated with lake sediments and peat bogs. The persistence in palaeobotanical and palaeopalynological studies will decisively contribute to disentangle the paleodiversity, palaeoecology, and add crucial information on insular plant phylogeny and biogeography.
The specimen described herein and assigned to 'Xyophorus' sp. (Mammalia, Xenarthra, Tardigrada) was collected in the locality Cerro Zeballos, northwestern Chubut Province, Argentina. The fossiliferous sediments bearing the specimen are correlated with Collón Curá Formation. The specimen has the features described for other members of 'Xyophorus' (e.g. shape and size of the molariforms, relationship between diastema length, m1 and m2 length) and has a Diastema Length/Tooth Row Length index (DL/TRL index) of ca. 14, between that of 'X.' villarroeli (12.07) from the Mauri Formation, Bolivia (ca. 10.3 Ma) and that of 'X.' bondesioi (16.45) from Arroyo Chasicó Formation, Argentina (ca. 10-8.7 Ma). The relationship between DL/TRL index and age of the bearing sediments, would suggest a Tortonian age (late Miocene) for the deposits of Collón Curá Formation at Cerro Zeballos, which results in a 'younger age' compared to the middle Miocene age traditionally accepted for the Collón Curá Formation bearing the Colloncuran fauna sensu stricto. Although no absolute ages for Cerro Zeballos are available yet, the geographic proximity of Cerro Zeballos to Cushamen River (with levels dated at ca. 11.2 Ma) supports the tentative Tortonian age indicated by the presence of 'Xyophorus' sp.
Hypolophin 'dasyatids' are a common group of large stingrays today frequenting the Indo-Pacific inshores. Being often harvested in their restricted area, few are known about their biology and their evolutionary history despite a very peculiar dental pattern making it easy to track their fossil record. An abundant material consisting of isolated teeth from Late Bartonian (38-40 Ma) lagoonal deposits of Djebel el Kébar, Tunisia, allows to describe a new stingray, Pastinachus kebarensis nov. sp. This taxon represents the oldest occurrence for this genus but also the oldest fossil record for hypolophins. A dental comparison of these fossils with 3D rendered models of fresh specimens testifies that early hypolophin representatives had already a strongly arcuate and bulbous upper jaw, interlocking with a broad and elongated tooth plate on the lower jaw. This new fossil and its fossil relatives (here updated), indicate a pre-Bartonian origination for hypolophins in western Neotethys, and reveal a rapid and widespread colonization of the proto-Mediterranean Sea, western Atlantic and Indo-Pacific coasts during the late Paleogene-early Neogene. Finally, it is worth noting that early hypolophin representatives seemingly entered freshwater habitats occasionally as modern cowtail stingrays do.
A digital cranial endocast of the specimen UFRGS-PV-596-T of Riograndia guaibensis was obtained from μCT scan images. This is a small cynodont, closely related to mammaliaforms, from the Late Triassic of Brazil. Riograndia has large olfactory bulb casts and the cerebral hemispheres region is relatively wider than in other non-mammaliaform cynodonts. Impressions of vessels were observed and a conspicuous mark on the dorsal surface was interpreted as the transverse sinus. The calculated encephalization quotient is greater than the range seen in most other non-mammaliaform cynodonts. The ratios between linear and area measurements of the dorsal surface suggest four evolutionary changes from a basal eucynodont morphology to mammaliaforms, involving an evolutionary increase of the relative size of the olfactory bulbs and the width of the cerebral hemispheres and cerebellum. The data supports the hypothesis of the neurological evolution of the mammalian lineage starting with a trend for an increase of the olfactory bulbs, which is associated with adaptations in the nasal cavity. This trend is suggested to be linked to the selective pressures for small-sized faunivorous, and probably nocturnal, animals, and represents an initial improvement of the sensory receptor system, subsequently leading to further development of the 'superior' structures for sensorial processing and integration.
We analyse the crest homologies of lower deciduous premolars (Dp4) of South American caviomorphs in a comparative context including other hystricomorphs and under a dynamic topological criterion. An hexalophodont pattern in which the three anteriormost crests are assumed to be the anterolophid, metalophulid I and metalophulid II, respectively, is proposed as ancestral morphology. Simplified pentalophodont morphologies would have resulted from loss of the metalophulid I, and distinct transformation pathways are recognised especially for Octodontoidea and Cavioidea. A basal octodontoid morphological pattern can be recognised in the fossil record from as early as the middle Eocene, supporting that an initial divergence among major clades of caviomorphs had already occurred by this time. Programs for identifying potentially useful dental characters in phylogeny and taxonomy of caviomorphs need to be revised. Interpreting lophids as dynamic components in the morpho-functional variation of molars, rather than as static landmarks, is central for understanding dental evolution in these rodents.
Recently, the fossil record of rodents from southwestern Brazilian Amazonia has been reviewed with regards to its diversity as well as its ecological relationships. In the reviews, the necessity to report new specimens collected with stratigraphic control was stated. Here, a new dinomyid specimen collected during a 2015 expedition to the Niterói locality, Acre River, is reported. The material is a fragment of skull with the right P4-M1 and the left P4-M2 preserved. The cheek teeth are protohypsodont, a characteristic employed to differentiate Potamarchinae dinomyids from the euhypsodont dinomyids Eumegamyinae and Tetrastylinae. The occlusal surface of the cheek teeth is composed of lophs with interruptions, showing little wear, which suggests that the specimen is not fully ontogenetically developed. The specimen has a unique combination of characters (protohypsodont and pentalophodont cheek teeth, with the leading edges of similar thickness to the trailing edges, and presence of a groove on the bottom of the infraorbital foramen) not present in other known dinomyids, which led us to erect a new taxon. The abundant and diverse fossil record of protohypsodont dinomyids suggests that an important radiative event may have occurred during the middle-late Miocene of northern South America. http://zoobank.org/urn:lsid:zoobank.org:pub:E082C3C6-47B6-4D83-9009-A64879AAFC7A http://www.zoobank.org/NomenclaturalActs/16235A7B-A261-445E-8DD4-940AB21DCB06
The Kopet-Dagh Basin is a large sedimentary basin in northeastern Iran that host the giant Khangiran and Gonbadli gas fields. The Mozduran Formation with its various sedimentary facies is an important reservoir widely distributed in the basin. A sedimentological analysis of Upper Jurassic Mozduran Formation resulted in an accurate reconstruction of the sedimentary environments and the sequence stratigraphic framework south of Aghdarband. The strata consist of six different facies associations including 12 carbonate, one evaporate and two siliciclastic subfacies. On the basis of their various components, structural and textural characteristics, these facies were deposited on a homoclinal ramp in tidal flat to open marine environments ranging from supratidal to subtidal settings. Facies A1 and A2 represent open marine, B1-B4 Shoal, C1-C4 lagoonal and D1, D2, E, T1 and T2 tidal flat and Salina environments. In addition, based on detailed field and laboratory studies on the facies architecture, several large-scale (long-term) depositional sequences could be distinguished in the stratigraphic sections of the study area. These sequences are composed of LST, TST and HST that are separated by a SB1 and SB2 sequence boundaries. The paleogeography of the study area during the Late Jurassic time is reconstructed in five block diagrams.