A novel trophic relationship between cassid gastropods and mysticete whale carcasses

Large cassid gastropods found in close association with Oligocene mysticete whale skeletons in a deep water setting indicate a novel trophic relationship. Bones of early mysticetes are preserved in close association with a recurring assemblage of bivalve taxa that are common components of fossil and recent hydrothermal vent and cold methane seep localities. Living members of these bivalve groups harbor sulfide-oxidizing autotrophic bacteria and comparisons with recent whale-falls indicate that they utilized bone-oil seepage. But unlike recent whale-falls, this fossil invertebrate assemblage is volumetrically dominated by large individuals of the cassid gastropod Liracassis apta that are preserved with their apertures adhering to the bone surfaces. Comparisons with recent cassoidean taxa and their ecological settings suggests that Liracassis apta belongs to the subfamily Oocorythinae, not Cassininae, and was an opportunistic scavenger in deep water, low oxygen environments. Oocorythine gastropods radiated rapidly on the northeastern Pacific margin during the Late Eocene and Oligocene to become the most commonly recorded gastropod in shelf and slope settings.     

DISTYLOMYIDAE FAM. NOV. (?CTENODACTYLOIDEA, RODENTIA) FROM NEI MONGOL, CHINA

<正> IntroductionA pair of rodent lower jaws believed belonging to one and the same individual were collected by the present author from Upper Oligocene Yikebulage Formation in Qianlishan district,Ih Ju League(=Yih Ju Meng),Nei Mongol,in 1978 The affinity searching of the lower jaws has really been a brain-racking one. At first glance I was struck by the similarity between     

内蒙阿左旗乌兰塔塔尔中渐新世的梳趾鼠类

本文描述和比较了发现在我国内蒙古阿左旗乌兰塔塔尔地区中渐新统的三属七种啮齿类梳趾鼠科化石,其中包括三个新种.并对某些种类的归属和性质做了初步的讨论.     

记内蒙古Juxia一新种

本文记述了在内蒙古沙拉木伦额尔登敖包地区第三系下渐新统乌兰戈楚组中发现的始巨犀的一个新种:寿氏始巨犀(Juxia shoui)。据其前臼齿及鼻切迹的位置等特点,这一新种当为始巨犀属中比较进步的一个成员,是包氏始巨犀和巨犀之间的过渡类型的犀类动物。     

DISCOVERY OF TWO MID-TERTIARY MAMMALIAN FAUNAS FROM HAIYUAN, NINGXIA, CHINA

Inl988-199otheRegionalGeologicalSurveyTeamoftheGeologicalBureauofNingxia(RGSN)foundsomefossilmammalsinthelowerpartoftheHo11g1iugouFormationandtheupperpartoftheOligocene.Inl992ajointteamoflnstituteofVertebratePaleontologyandPaleoanthropo1ogy,AcademiaSinica(IVPP),andtheRGSNwenttoHaiyuailCountyandcollectedmorefossilmamma1sfromtheYuanjia-wowoareausi11gascreen-washingmethodThemammalfaunafromthelowerpartoftheHongliugouFormationiscomposedofAprotodonsp.,Indricotheriidaeindet.,Rhinoceroti…     

Phylogenomic study of Amorphophallus (Alismatales; Araceae): When plastid DNA gene sequences help to resolve the backbone subgeneric delineation

Encompassing ca. 200 species distributed in paleotropical Africa and Asia, Amorphophallus is one of the largest genera of Araceae. In spite of the great economic interest in its glucomannan production, only a few studies have attempted to grasp the evolutionary history of this genus. In the current state of knowledge, four main clades, mostly linked to biogeographical delineation, have been identified from phylogenies based on a few genes. However, relationships among and within these clades still remain unclear, due to the rapid radiation that occurred during the early evolutionary history of the genus. Here, we generated genome skimming libraries for 43 specimens from 36 species distributed across the 4 clades, which allowed us to produce a phylogenetic matrix for a set of 71 plastid genes. Our phylogenies confirm the monophyly of these clades but show a new and well-resolved arrangement among these clades. Our analyses therefore provide a new scenario and timeline for the evolution of the main Amorphophallus clades, consistent with the morphological characteristics of the clades. The inferred scenario is also in agreement with climate dynamics and the onset of long-distance dispersal by the earliest migratory birds near the Oligocene/Miocene transition around 23 million years ago. Our study provides an up-to-date baseline to understand biogeographic and ecological processes that shaped the current diversity and distribution of Amorphophallus, paving the way for larger-scale phylogenomic studies based on plastid and nuclear genomes.     

The humerus of Aegyptopithecus zeuxis: a primitive anthropoid

Two complete humeri of Aegyptopithecus zeuxis have been recovered from Oligocene deposits in the Fayum Province of Egypt. These new specimens support previous interpretations of the locomotor adaptations of this species and indicate that A. zeuxis was a robust, slowly moving arboreal quadruped. While the previously described distal articular region of the humerus is virtually identical with the same region in many extant ceboids and the Miocene hominoid Pliopithecus vindobonensis, the more proximal parts of the humerus show many primitive "prosimianlike" features not found the limbs of extant anthropoids. The primitive features include the absence of a distinct deltoid plane, a broad shallow bicipital groove, a large brachialis flange, and an entepicondylar foramen. In most features, the humerus of Aegyptopithecus zeuxis is more primitive than the hypothetical last common ancestor of extant cercopithecoids and hominoids based on neontological comparisons. This supports other lines of evidence indicating that the hominoids from the Egyptian Oligocene are morphologically ancestral to both Old World monkeys and apes.     

Les échos de la phase aquitano-burdigalienne dans la coupe de Dellaca Bianca (Val Scrivia,bassin Liguro-piémontais,Italie)

The geologic section of the Torrente Scrivia in 061 the vicinity of Rigoroso is generally reported as an conformable sequence in Oligocene and Miocene strata.In fact, it has suffered important reworkingsduring Lower Miocene and this event is not only evident in sedimentology but also in paleontology. Locally, these events reflect tectonic motions more strongly marked in the north-eastern part of the ligurian piemontese basin.Consequently, the result is that the geologicsection concerned could not be satisfactory referring to Lower Miocene.     

Réflexions critiques sur l'écologieet la systématique des Lingules actuelles et fossiles

New topics on ecology and systematics of recent and fossil Lingulids lead to an obvious revision of our knowledges on this zoological group. At first, the recent species need systematics and taxonomy on the bases of new described specific criteria (as, morphology of deltidial areas, muscle disposition); the results are briefly indicated. But, in fossil species, disorder and disparity of used characteristics are emphasized.The general conceiving on ecology of Lingulids are reviewed and discussed, especially on bathymetry and salinity; sediment and oxygenation conditions; taphocoenosis and lingulid «communities. On recent species, all these points are also studied, especially some ecological requirements (salinity, bathymetry, grain size), and mechanism of burrowing ability, burrow living positions in the sediments, as shell preservations after death and fossilization, to facilitate the paleobiotope interpretations. Recent animals are euryhalin, surviving at salinities from about 13 to 42‰; they could be considered as well adapted to waters with strong salinity fluctuations. They show preference to fine sand bottoms (lowest particle size about 40–60 μm). Their bathymetric distribution occurs between 0 and about 500 m (Lingula especially between 5–50 m; Glottidia 15–70 m). The isotherms 8–10°C seem to restrict their geographical and bathymetric distribution.Therefore, some post-palaeozoic lingulid bedsare studied or redescribed on the bases of the above discussed characteristics, and new interpretations on the environmental situation are given (Trias of Vosges Mountains; Oligocene from Japan; Eocene of London Basin). More caution must be used in study of fossil Lingulids that are not especially animals living in infralittoral bottoms with low salinity and deficient oxygenation, as generally accepted.     

Tsuga seed cones from the late Paleogene of southwestern China and their biogeographical and paleoenvironmental implications

Six Tsuga ovuliferous/seed cone impression fossils were discovered from the late Eocene (34.6 ± 0.8 Ma) Lawula Formation in Mangkang County, eastern Tibet and the early Oligocene (32 ± 1 Ma) lacustrine deposits in Lühe Basin, Nanhua County, Yunnan Province. These two fossil sites are both located in southwestern China, ∼800 km apart from each other. These fossils represent the oldest records of this genus in southwestern China, even earliest reliable macrofossil records of this genus in the world. These well-preserved seed cones provide sufficient materials for the establishment of Tsuga asiatica Wu et Zhou n. sp. to accommodate five specimens, leaving one to be assigned to T. cf. dumosa Eichler (cf. Wu et Zhou). Both qualitative and quantitative comparisons with other cone fossils and cones of all living species of the genus suggested that T. asiatica shares more similarities with one of the basal species of the genus T. heterophylla. The discovery of late Paleogene macrofossil records of Tsuga in southwestern China supports the previous hypothesis of the early disposal routes of this coniferous genus predicted by phylogenetic analysis. The elevation ranges and the climate requirements of living species that are closely related to our fossils suggest that the southeastern edge of the Qinghai-Tibetan Plateau should be much warmer, and wetter in late Paleogene than nowadays.