New chiropterans from the middle Eocene of Shanghuang (Jiangsu Province,Coastal China): new insight into the dawn horseshoe bats (Rhinolophidae) in Asia

Until recently, the fossil record of Paleogene bats in Asia primarily included extinct families (i.e. ‘Eochiroptera’) from the early Eocene of Vastan in India and from the middle‐late Eocene of the Liguanqiao and Yuanqu basins in central China. Here, we describe a new fauna of Chiroptera from the middle Eocene Shanghuang fissure fillings of China. The fauna includes abundant material referred to a new rhinolophid (Protorhinolophus shanghuangensis gen. and sp. n.), one specimen of a possible rhinopomatid and several indeterminate rhinolophoids. This new bat assemblage constitutes the earliest record of extant families of microbats in Asia. Because it lacks representatives of ‘Eochiroptera’, this Shanghuang bat fauna indicates significant turnover in Asian bat communities. The dental pattern of P. shanghuangensis shows a mosaic of primitive and derived features (‘Eochiroptera’ vs Rhinolophidae dental characteristics), suggesting that this taxon occupies a basal position among the Rhinolophidae. Rhinolophids were already well diversified at the end of the late Eocene in Europe. Interestingly, many dental characteristics of Protorhinolophus are also found in a primitive rhinolophoid taxon, Vaylatsia, from the middle Eocene to late Oligocene of Europe, supporting a close relationship between these taxa. These affinities testify to the widespread Eurasian distribution of rhinolophoids during the Eocene and are consistent with a westward dispersal of the group from eastern Asia to Europe owing to the greater antiquity of Protorhinolophus.     

Unusual histology and morphology of the ribs of mosasaurs (Squamata)

We report the presence of two previously unrecognized features in the dorsal ribs of mosasaurs: first, the presence of extremely dense, pervasive extrinsic fibres (anchoring soft tissue to bone, sometimes called Sharpey's fibres); and second, high intraspecific variation in costal bone compactness. Extensive extrinsic fibres are developed in the dorsal ribs of the mosasaurs Tylosaurus proriger and Eonatator sternbergi. The dorsal ribs of these mosasaurs are also characterized by a longitudinally ridged texture that almost completely covers the bone. Pervasive extrinsic fibres and ridged textures are absent in the mosasaur Selmasaurus russelli as well as the dorsal ribs of extant semi‐aquatic reptiles (e.g. crocodyliforms) and mosasaurs' close extant relatives and analogues (e.g. snakes and varanids). Similar ridged textures characterize the dorsal ribs of several other mosasaur taxa but are developed to a lesser extent (e.g. Mosasaurus, Clidastes, Platecarpus and Ectenosaurus), but in no other taxa have pervasive extrinsic fibres been reported. We interpret these osteohistological features in T. proriger and E. sternbergi as evidence of tendinous attachment of extensive and highly differentiated axial musculature capable of producing great stresses, most likely related to stabilization of the trunk relative to contralateral movements of the tail during carangiform locomotion. We also report the compactness indices (percentage of space occupied by bone rather than cavities) for these large mosasaur ribs, which are much higher than previously reported. This suggests high intraspecific variation in bone compactness that complicates its use in reconstructing mosasaur palaeoecology.     

Teeth of extant Polypteridae and Amiidae have plicidentine organization

The study of teeth of the lower jaws of Amia calva and Polypterus senegalus, with non -destructive X-ray tomography, has revealed that there are dentine folds in the tooth pulp cavity in both species. These folds are simple and present only in the base of the pulp cavity where they strengthen the fixation of teeth on the jaw. So the teeth of these two basal actinopterygian taxa have a simplexodont type of plicidentine like the extinct †Cheirolepis and various extant teleostean predators, whereas the extant Lepisosteids, the sister group of Amiidae, have polyplocodont plicidentine. The phylogenetic/adaptive significance of this simplexodont plicidentine is discussed.     

Marsileaceaephyllum, a new genus for marsileaceous macrofossils: leaf remains from the Early Cretaceous (Albian) of southern Gondwana

Three new taxa from Albian, Early Cretaceous assemblages in Gondwana (Australia and Antarctica) and two previously described fossils from the Late Cretaceous and Eocene of North America are attributable to the heterosporous semi-aquatic fern family Marsileaceae. They are assigned to Marsileaceaephyllum, a morphotaxon erected here for sterile remains (whole plants, and isolated leaves and leaflets) of Marsileaceae. The Gondwanan taxa, Marsileaceaephyllum lobatum and Marsileaceaephyllum spp. B-C, have either a cruciform leaflet arrangement or dichotomous and anastomosing venation characteristic of modern Marsileaceae. Two previously established taxa, Marsilea johnhallii and Marsilea sp., which represent sterile Marsileaceae, are also transferred to the new genus (now Marsileaceaephyllum johnhallii and Marsileaceaephyllum sp. A, respectively). Examination of all fossil venation patterns reveals four new venation types not present in extant taxa, suggesting that most fossil Marsileaceae (leaves) are distinct from extant genera, and are likely members of extinct lineages. This is further supported by the absence of modern megaspore types in the Early Cretaceous.     

Phylogenetic implications of the some cranial features of the porcupine pufferfish <Emphasis Type="Italic">Pshekhadiodon</Emphasis> (Tetraodontiformes,Diodontidae) from the Eocene of the Northern Caucasus

The well-preserved skull of the diodontid fish Pshekhadiodon parini Bannikov et Tyler, 1997 from the Eocene of the North Caucasus has plesiomorphic conditions for four character that are apomorphic in all extant taxa, and the family Diodontidae is herein separated into two subfamilies, the Diodontinae for all of the extant taxa and the Pshekhadiodontinae for Pshekhadiodon and very tentatively for the three other Eocene taxa of the family, all from Monte Bolca, Italy.     

Osteopathology in Rhinocerotidae from 50 Million Years to the Present

Individual elements of many extinct and extant North American rhinocerotids display osteopathologies, particularly exostoses, abnormal textures, and joint margin porosity, that are commonly associated with localized bone trauma. When we evaluated six extinct rhinocerotid species spanning 50 million years (Ma), we found the incidence of osteopathology increases from 28% of all elements of Eocene Hyrachyus eximius to 65–80% of all elements in more derived species. The only extant species in this study, Diceros bicornis, displayed less osteopathologies (50%) than the more derived extinct taxa. To get a finer-grained picture, we scored each fossil for seven pathological indicators on a scale of 1–4. We estimated the average mass of each taxon using M1-3 length and compared mass to average pathological score for each category. We found that with increasing mass, osteopathology also significantly increases. We then ran a phylogenetically-controlled regression analysis using a time-calibrated phylogeny of our study taxa. Mass estimates were found to significantly covary with abnormal foramen shape and abnormal bone textures. This pattern in osteopathological expression may reflect a part of the complex system of adaptations in the Rhinocerotidae over millions of years, where increased mass, cursoriality, and/or increased life span are selected for, to the detriment of long-term bone health. This work has important implications for the future health of hoofed animals and humans alike.     

Postcranial pneumaticity: an evaluation of soft-tissue influences on the postcranial skeleton and the reconstruction of pulmonary anatomy in archosaurs

Postcranial pneumaticity has been reported in numerous extinct sauropsid groups including pterosaurs, birds, saurischian dinosaurs, and, most recently, both crurotarsan and basal archosauriform taxa. By comparison with extant birds, pneumatic features in fossils have formed the basis for anatomical inferences concerning pulmonary structure and function, in addition to higher-level inferences related to growth, metabolic rate, and thermoregulation. In this study, gross dissection, vascular and pulmonary injection, and serial sectioning were employed to assess the manner in which different soft tissues impart their signature on the axial skeleton in a sample of birds, crocodylians, and lizards. Results from this study indicate that only cortical foramina or communicating fossae connected with large internal chambers are reliable and consistent indicators of pneumatic invasion of bone. As both vasculature and pneumatic diverticula may produce foramina of similar sizes and shapes, cortical features alone do not necessarily indicate pneumaticity. Noncommunicating (blind) vertebral fossae prove least useful, as these structures are associated with many different soft-tissue systems. This Pneumaticity Profile (PP) was used to evaluate the major clades of extinct archosauriform taxa with purported postcranial pneumaticity. Unambiguous indicators of pneumaticity are present only in certain ornithodiran archosaurs (e.g., sauropod and theropod dinosaurs, pterosaurs). In contrast, the basal archosauriform Erythrosuchus africanus and other nonornithodiran archosaurs (e.g., parasuchians) fail to satisfy morphological criteria of the PP, namely, that internal cavities are absent within bone, even though blind fossae and/or cortical foramina are present on vertebral neural arches. An examination of regional pneumaticity in extant avians reveals remarkably consistent patterns of diverticular invasion of bone, and thus provides increased resolution for inferring specific components of the pulmonary air sac system in their nonavian theropod ancestors. By comparison with well-preserved exemplars from within Neotheropoda (e.g., Abelisauridae, Allosauroidea), the following pattern emerges: pneumaticity of cervical vertebrae and ribs suggests pneumatization by lateral vertebral diverticula of a cervical air sac system, with sacral pneumaticity indicating the presence of caudally expanding air sacs and/or diverticula. The identification of postcranial pneumaticity in extinct taxa minimally forms the basis for inferring a heterogeneous pulmonary system with distinct exchange and nonexchange (i.e., air sacs) regions. Combined with inferences supporting a rigid, dorsally fixed lung, osteological indicators of cervical and abdominal air sacs highlight the fundamental layout of a flow-through pulmonary apparatus in nonavian theropods.     

A subordinal classification of frogs (Amphibia: Anura)

Two new anuran suborders, based on two states of the trigeminofacial ganglion character complex are proposed. A subsidiary character is the presence or absence of free ribs in extant taxa. These new suborders are more clades (sister groups) than sequential levels of organization. Discoglossoidei, retaining separate trigeminal and facial ganglia and free ribs, encompasses only Leiopelmatidae and Discoglossidae, although by definition it would include the common ancestor of both lineages. Ranoidei have the trigeminal and facial ganglia fused and extant taxa lack free ribs. This group includes all other frogs.
Only the superfamiliesPelobatoidea and Pipoidea are reallocated by the new arrangement. The former are now regarded as representing the ranoidean stem group. Both laival and adult morphology show that pipoids are highly derived rather than primitive frogs, and their trigeminofacial systems show that they are ranoideans rather than discoglossoideans. They presumably are ultimately derived from pelobatoids, but the known taxa are too specialized for direct derivation and there must have been an intermediate group with pipoid tadpoles but without extreme specializations for either fossorial or aquatic life.     

The fossil record of Glypturus Stimpson, 1866 (Crustacea,Decapoda, Axiidea,Callianassidae) revisited,with notes on palaeoecology and palaeobiogeography

Abstract: The fossil record of the callianassid genus Glypturus (Decapoda, Axiidea) is re‐evaluated. Our systematic revision, both of extant and fossil taxa, is based on major cheliped morphology only, thus providing an important impetus for palaeontological studies. Both spination and tuberculation of chelipeds are herein considered of great taxonomic importance. Presence of spines on the upper margins of the merus and propodus and the lower margin of the carpus are significant for generic assignment, whereas the extent of tuberculation on lateral surfaces of the propodus is important for assignment at the species level. Altogether, four extant and six exclusively fossil species of Glypturus are recognized. Several extinct callianassid taxa are now transferred to the genus, namely Callianassa berryi, Callianassa fraasi, Callianassa munieri, Callianassa pugnax and Callianassaspinosa; Callianassa pseudofraasi is considered a junior synonym of C. fraasi. Based on a comparison of ecological preferences of extant representatives, the presence of Glypturus in the fossil record is considered to be linked with tropical to subtropical, nearshore carbonate environments of normal salinity. We argue that Glypturus is of Tethyan origin, with a stratigraphical range going as far back as the Eocene. Since then, the genus migrated both westwards and eastwards, establishing present‐day communities in the western Atlantic and Indo‐West Pacific which both comprise several distinct species. In the presumed area of origin, the genus does no longer occur today. The exlusively fossil (middle Eocene) genus Eoglypturus from Italy is considered closely related to Glypturus and is thus assigned to the subfamily Callichirinae as well.     

FOSSIL CERATOPHYLLUM (CERATOPHYLLACEAE) FROM THE TERTIARY OF NORTH AMERICA

Fossil fruits and a vegetative axis assignable to the extant genus Ceratophyllum are described from four North American Tertiary localities. Fossil fruits assignable to the extant species C. muricatum and C. echinatum are reported from the Eocene Green River and Claiborne formations, and the Miocene Esmerelda Formation, respectively. An extinct species, C. furcatispinum, is described from the Paleocene Fort Union Formation and represents the oldest published report of Ceratophyllum in the fossil record. The existence of extant angiosperm species in the Eocene is very unusual and may be attributable in this case to slow evolutionary rates and unusual evolutionary properties associated with hydrophily in the genus Ceratophyllum.     

Systematics and evolution of the Pan‐Alcidae (Aves,Charadriiformes)

Puffins, auks and their allies in the wing‐propelled diving seabird clade Pan‐Alcidae (Charadriiformes) have been proposed to be key pelagic indicators of faunal shifts in Northern Hemisphere oceans. However, most previous phylogenetic analyses of the clade have focused only on the 23 extant alcid species. Here we undertake a combined phylogenetic analysis of all previously published molecular sequence data (～ 12 kb) and morphological data (n = 353 characters) with dense species level sampling that also includes 28 extinct taxa. We present a new estimate of the patterns of diversification in the clade based on divergence time estimates that include a previously vetted set of twelve fossil calibrations. The resultant time trees are also used in the evaluation of previously hypothesized paleoclimatic drivers of pan‐alcid evolution. Our divergence dating results estimate the split of Alcidae from its sister taxon Stercorariidae during the late Eocene (～ 35 Ma), an evolutionary hypothesis for clade origination that agrees with the fossil record and that does not require the inference of extensive ghost lineages. The extant dovekie Alle alle is identified as the sole extant member of a clade including four extinct Miocene species. Furthermore, whereas an Uria + Alle clade has been previously recovered from molecular analyses, the extinct diversity of closely related Miocepphus species yields morphological support for this clade. Our results suggest that extant alcid diversity is a function of Miocene diversification and differential extinction at the Pliocene–Pleistocene boundary. The relative timing of the Middle Miocene climatic optimum and the Pliocene–Pleistocene climatic transition and major diversification and extinction events in Pan‐Alcidae, respectively, are consistent with a potential link between major paleoclimatic events and pan‐alcid cladogenesis.     

INVESTIGATIONS OF ANGIOSPERMS FROM THE EOCENE OF NORTH AMERICA: JUGLANDACEOUS WINGED FRUITS

The winged fruits of Engelhardia have been reported in many early Tertiary floras in the northern Hemisphere. Recent systematic revisions of the extant genera, Engelhardia, Oreomunnea, and Alfaroa provide a helpful guide to the study of the fossil fruits. Fruit form, venation, nut septations and flower parts are features that separate the extant Asian Engelhardia from the American Oreomunnea. Four types of fossil winged fruits can be recognized in Middle Eocene sediments of southeastern North America: Engelhardia, Paraoreomunnea gen. n., Paleooreomunnea gen. n., and Pararengelhardia. Both Paleooreomunnea and Paraengelhardia represent extinct lines; no living forms have similar winged fruits. The fossil fruits of Engelhardia and Paraoreomunnea are similar to the fruits of extant Engelhardia and Oreomunnea, respectively. The fossil taxa reported in this paper were sympatric. The present allopatric distribution of Engelhardia and Oreomunnea is the result of Neogene regional extinctions. Engelhardia and Oreomunnea have probably been distinct genera since early Paleogene time.     

A reassessment of Eocene parrotlike fossils indicates a previously undetected radiation of zygodactyl stem group representatives of passerines (Passeriformes)

In the past years, various Eocene fossil birds were described as stem group representatives of the zygodactyl Psittaciformes (parrots). These birds show quite disparate morphologies, which cast some doubt on the correct assignment of all of them to the psittaciform stem group. A reassessment of their affinities is further needed, because it was recently proposed that among extant birds, Psittaciformes and Passeriformes (passerines) form a clade and that passerines possibly derived from a zygodactyl ancestor. Here, phylogenetic analyses are performed, which for the first time also include representatives of the Zygodactylidae, the extinct zygodactyl sister taxon of the Passeriformes. The early Eocene Psittacopes was originally described as a stem group representative of Psittaciformes. However, none of the present analyses supported psittaciform affinities for Psittacopes and instead recovered this taxon in a clade together with zygodactylids and passerines. Also part of this clade are the early Eocene taxa Pumiliornis and Morsoravis, and it is detailed that Psittacopes and the long‐beaked and presumably nectarivorous Pumiliornis, with which it has not yet been compared, are very similar in their postcranial osteology. The present analysis corroborates the hypothesis of a zygodactyl stem species of passerines. To account for these results, Psittacopes is here assigned to a new higher‐level taxon and a new name is also introduced for the clade including Zygodactylidae and Passeriformes.     

The systematics of right whales (Mysticeti: Balaenidae)

Balaenidae (right whales) are large, critically endangered baleen whales represented by four living species. The evolutionary relationships of balaenids are poorly known, with the number of genera, relationships to fossil taxa, and position within Mysticeti in contention. This study employs a comprehensive set of morphological characters to address aspects of balaenid phylogeny. A sister‐group relationship between neobalaenids and balaenids is strongly supported, although this conflicts with molecular evidence, which may be an artifact of long‐branch attraction (LBA). Monophyly of Balaenidae is supported, and three major clades are recognized: (1) extinct genus Balaenula, (2) extant and extinct species of the genus Eubalaena, and (3) extant and extinct species of the genus Balaena plus the extinct taxon, Balaenella. The relationships of these clades to one another, as well as to the early Miocene stem balaenid, Morenocetus parvus, remain unresolved. Pliocene taxa, Balaenula astensis and Balaenula balaenopsis, form a clade that is the sister group to the Japanese Pliocene Balaenula sp. Eubalaena glacialis and Pliocene Eubalaena belgica, are in an unresolved polytomy with a clade including E. japonica and E. australis. Extant and fossil species of Balaena form a monophyletic group that is sister group to the Dutch Pliocene Balaenella, although phylogenetic relationships within Balaena remain unresolved.     

Mandibular remains of Procardiomys martinoi Pascual, 1961 (Hystricognathi,Cavioidea) from the Arroyo Chasicó Formation (early late Miocene) of Argentina: anatomy and the phylogenetic position of the genus within Caviidae

Hydrochoerinae is a clade of caviomorph rodents broadly distributed in South America, which includes the maximum body size recorded among extant rodent taxa. The most basal forms of this group are an assemblage of small to medium body size extinct taxa with a plesiomorphic dentition, traditionally clustered in the group cardiomyines. One of the oldest known cardiomyine is Procardiomys martinoi (Chasicoan South American Land Mammal Age SALMA; early late Miocene), which was known only from the holotype, a fragmentary palate with the left and right molar series. New mandibular remains from the Arroyo Chasicó Formation (Chasicoan SALMA) are described and identified here as belonging to P. martinoi because they share a unique combination of characters (as well matching in size) with the upper dentition of the holotype. These materials help in critically reviewing the taxonomic identification of the mandibular remains previously assigned to Procardiomys and allow testing the phylogenetic affinities of this taxon within Caviidae. P. martinoi is depicted as one of the most basal forms of Hydrochoerinae, placed basally on the lineage leading to extant capybaras after the split between the common ancestor of Kerodon and Hydrochoerus.

http://zoobank.org/F60356E0-CB8E-48C2-BF86-429E347A9579     

Microanatomy of the amniote femur and inference of lifestyle in limbed vertebrates

The femoral microanatomy of 155 species of extant amniotes (57 species of mammals, 15 species of turtles, 56 species of lepidosaurs, and 27 species of birds) of known lifestyle is studied to demonstrate a possible link between some basic parameters of bone structure and specific lifestyles, as well as phylogenetic relationships between taxa. Squared change parsimony with random taxon reshuffling and pairwise comparisons reveal that most compactness and size parameters exhibit both phylogenetic and ecological signals. A discriminant analysis produces several inference models, including a ternary model (aquatic, amphibious, terrestrial) that yield the correct lifestyle in 88% of the cases. These models are used to infer the lifestyle of three extinct Permian temnospondyls: Eryops megacephalus, Acheloma dunni, and Trimerorhachis insignis. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 644–655.     

Significance of primate petrosal from Middle Eocene fissure-fillings at Shanghuang, Jiangsu Province, People's Republic of China

An isolated petrosal bone belonging to a diminutive primate is reported from Middle Eocene fissure-fills near Shanghuang (southern Jiangsu Province, People's Republic of China), the type locality of several newly described primates (Eosimias sinensis, a basal anthropoid; Adapoides troglodytes, a basal adapinan; Tarsius eocaenus, a congener of extant tarsiers; and Macrotarsius macrorhysis, the first Asian representative of an otherwise exclusively North American genus). Because of its fragmentary condition and unique combination of characters, the Shanghuang petrosal cannot be assigned unambiguously to any of the Shanghuang primate taxa known from dental remains. However, the possibility that the petrosal represents either an adapid or a tarsiid can be dismissed because it lacks defining basicranial apomorphines of these groups. By contrast, the element does present arterial features consistent with its being haplorhine. Deciding between the likeliest candidates for its allocation—Omomyidae and Eosimiidae—is difficult, in part because it is not known what (or even whether) basicranial characters can be used to distinguish these clades. If the Shanghuang petrosal is that of an cosimiid, as both direct and indirect evidence appears to indicate, the following implications emerge: (1) as long suspected on other grounds, anthropoids share a closer evolutionary history with Omomyidae (and Tarsiiformes) than they do with Adapidae (and Strepsirhini); (2) the specialised basicranial anatomy of extant anthropoids and their immediate cladistic relatives is derived from a primitive precursor whose otic morphology was like that of omomyids in most known respects; (3) the evolution of the defining dental and basicranial apomorphies of extant Anthropoidea has been distinctly mosaic in pattern.     

A brief review of the fossil history of the family Rosaceae with a focus on the Eocene Okanogan Highlands of eastern Washington State, USA, and British Columbia, Canada

Many of the oldest definitive members of the Rosaceae are present in the Eocene upland floras of the Okanogan Highlands of northeastern Washington State and British Columbia, Canada. Over a dozen rosaceous taxa representing extant and extinct genera of all four traditionally recognized subfamilies are known from flowers, fruits, wood, pollen, and especially leaves. The complexity seen in Eocene Rosaceae suggests that hybridization and polyploidy may have played a pivotal role in the early evolution of the family. Increased species diversity and the first appearance of additional modern taxa occur during the Late Paleogene in North America and Europe. The Rosaceae become increasingly important components of fossil floras during the Neogene, with taxa adapted to many habitats.