NATHALIE BARDET1, MARTA FERNÁNDEZ2, JOSÉ CARLOS GARCIA RAMOS3, LAURA PIÑUELA3, PEGGY VINCENT1 and XABIER PEREDA SUBERBIOLA4
1 UMR 5143 du CNRS, Dépt. Histoire de la Terre, MNHN, Paris, France (email@example.com, firstname.lastname@example.org); 2 Dept. Paleontología Vertebrados, Museo de La Plata, La Plata, Argentine (email@example.com), 3 Museo del Jurásico de Asturias, Colunga, Spain (firstname.lastname@example.org, email@example.com); 4 Universidad del País Vasco/E.H.U., Fac. de Ciencia y Tecnología, Dept. de Estratigrafía y Paleontología, Bilbao, Spain (firstname.lastname@example.org)
Iberian plesiosaurs: a juvenile specimen from the Lower Jurassic of Asturias, Northern Spain.
Mesozoic marine reptiles, especially Plesiosauria, are poorly known in the Iberian Peninsula except Triassic sauropterygians. From Spain, the only plesiosaur fossil record includes a 19th century specimen (now lost) from the Lower Jurassic of Asturias (Schulz, 1858) - one of the earliest plesiosaur discoveries, elasmosaurid and pliosaurid isolated teeth and vertebrae from the Lower Cretaceous of Castellón (Yagüe et al., 2003), and an isolated elasmosaurid tooth from the Late Cretaceous of the Basque Country (Bardet et al., 1999). From Portugal, only an incomplete plesiosaurid skull has been described from the Lower Jurassic (Sauvage, 1897-1898).
The new discovery of a partial skeleton from the Pliensbachian of Asturias improves our knowledge of plesiosaurs in Spain. The specimen includes vertebrae, ribs, limb and girdle elements. The incomplete and immature nature of the specimen precludes a precise systematical attribution. It is referred to as Plesiosauroidea indet. on the basis of centra roughly as long as wide and bicephalous cervical ribs. It represents one of the very few juvenile plesiosaur records worldwide and contributes to fill the Pliensbachian marine reptile fossil gap.
Bardet, N., Corral J.C. & Pereda Suberbiola X. 1999. Estudios del Museo de Ciencias Naturales de Alava , 14 (1), 373-380.
Schulz, G. 1858. Descripción geológica de Asturias . Madrid, 138 pp.
Yagüe, P., Ortega, F., Noè, L., Gasulla, J. M. & García, M. D. 2003. In: Pérez-Lorente, F. (Coord.), Dinosaurios y otros reptiles mesozoicos en España, Logroño, Ciencias de la Tierra, 26, 399-404.
Sauvage, H.-E. 1897-1898. Vertébrés fossiles du Portugal. Lisbonne, 46 pp.
Robin M.D. Beck, Henk Godthelp, Michael Archer & Suzanne J. Hand
School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia (email@example.com)
‘Ameridelphian’ and crown australidelphian marsupials from the Early Eocene of Australia. O)
It is now accepted that the ancestors of Australia’s unique marsupial fauna dispersed overland from South America (via Antarctica) at some time during the Late Cretaceous or Early Palaeogene. However, the timing and nature of the dispersal(s) remains somewhat unclear, in large part because only a single pre-Oligocene site containing marsupials - an Early Eocene (~55 MYA) freshwater lacustrine deposit near Murgon, south-east Queensland (Godthelp et al., 1992) - is currently known. Here we describe a number of significant specimens (some of which had previously been identified but remain unpublished) from this site that, together with the Murgon marsupials already named, shed light on this question. They include teeth referable to Peramelemorphia (bandicoots) – these being the oldest known members of the Australian marsupial crown-group -, as well as calcanea with the characteristic australidelphian ‘continuous lower ankle joint pattern’ (CLAJP). Intriguingly, dental material also reveals the presence of two genera of microbiotheres, a group previously known only from South America and Antarctica. Perhaps most significantly, two calcanea possess the plesiomorphic ‘separate lower ankle joint pattern’ (SLAJP), and so suggest the presence of ‘ameridelphians’ in Australia during the Palaeogene. We discuss the implications of these fossils for marsupial evolution and biogeography, in the context of a dated molecular phylogeny of extant marsupials and biogeographical evidence.
Godthelp, H., Archer, M., Cifelli, R., Hand, S. J., and Gilkeson, C. F. 1992. Earliest known Australian Tertiary mammal fauna. Nature 356: 514–516.
Michael J. Benton & Philip C. J. Donoghue
Department of Earth Sciences, University of Bristol, Wills Memorial Building, Queen's Road, Bristol, BS8 1RJ (Mike.Benton@bristol.ac.uk)
Dating the tree of life
The role of fossils in dating the tree of life has been misunderstood. Fossils can provide good minimum age estimates for branches in the tree, but maximum constraints on those ages are poorer. Current debates about which are the ‘best’ fossil dates for calibration are futile. Because fossil-based dates are constraints, and because molecular evolution is not perfectly clock-like
, analysts should use as many dates as possible. We provide ‘hard’ minimum and ‘soft’ maximum age constraints for 25 divergences among key genome model organisms; these should contribute to better understanding of the dating of the animal tree of life.
Paléobiodiversité, UMR 5143 CNRS, Département Histoire de la Terre, CP 38, Muséum National d'Histoire Naturelle, 8, rue Buffon, F-75005 PARIS, France (firstname.lastname@example.org)
A new mesotheriid (Mammalia, Notoungulata) from the Late Oligocene of Salla (Bolivia) and a preliminary study of early mesotheriids.
Among South American endemic notoungulates, mesotheriids constitute a peculiar group with a strange rodent-like habitus and hypsodont to hypselodont cheek teeth. They are first known in the South American fossil record from the Divisaderian [Early Oligocene] and persist until the Ensenadan [Early Pleistocene]. Their first representatives are traditionally recognized as members of the paraphyletic assemblage ‘trachytherinae’ and all included in the genus Trachytherus . Although the first remains assigned to Trachytherus were described more than a century ago, the ontogeny, range of morphological variation and systematics of its representatives are still poorly understood. Of course, study of such characteristics for these highly hypsodont notoungulates would be of great interest since it is very difficult to determine whether particular cheek teeth dimensions and morphological variation would have to be considered as inter- or intraspecific. For the first time, a large collection of mesotheriid specimens yielded by the Bolivian Salla Formation (Deseadan, Late Oligocene) and previously referred to T. spegazzinianus , were included in a large-scale analysis. Firstly, this has led to the description of a new species different from T. spegazzinianus . Secondly, cheek teeth variation range throughout ontogeny could be determined. This is currently by far the best known early mesotheriid species, shedding light on the confused systematics of the group. Moreover, distinction from the Patagonian species T. spegazzinianus confirms the faunal differences observed between Bolivian and Patagonian Deseadan localities. This may be attributed to age discrepancy and/or existence of a geographical and/or altitudinal barrier.
Virginie Bouetel & Christian de Muizon
UMR 5143 (MNHN, CNRS, UPMC), Département Histoire de la Terre, Muséum national d'Histoire naturelle, CP 38, 57 rue Cuvier, F-75005 Paris (email@example.com , firstname.lastname@example.org )
Are Cetotheriidae s.s. monophyletic? Piscobalaena nana Pilleri & Siber, 1989 gives a hint.
Pilleri & Siber, 1989 is a small fossil baleen-bearing mysticete from the Early Pliocene of the Pisco Formation, Peru. The holotype of this species is an incomplete skull (lacking the vertex) with associated tympanics. The description of five remarkably preserved new specimens of this taxon provides the opportunity to understand the intraspecific variation within one single fossil mysticete species. These specimens constitute an ontogenic series including one sub-adult animal, three adults and one old individual.
has been compared to five other fossil taxa (Nannocetus
) which are similar in morphology and age to the Peruvian species. A parcimony analysis of 101 morphological characters of the skull, auditory area and dentary tested on 23 taxa confirms the paraphyly of the traditional Cetotheriidae. It also suggests that six (Piscobalaena
) of the 12 studied fossil baleen mysticetes constitute a clade: the Cetotheriidae s.s. Its monophyly is supported by 10 characters of the skull (e.g. ascending processes of the maxillae contacting medially or very approximated at apex only), and five characters of the auditory area (e.g. anterior edge of facial foramen on the internal acoustic meatus is notched for the passage of the greater petrosal nerve.
The Cetotheriidae share with the Balaenopteridae the presence of an interdigitation of the rostral and cranial bones such as the posteriorly elongated ascending process of the maxilla. This condition reinforces the cranial architecture and could suggest a similar engulfment way of feeding as observed in the Balaenopteridae.
Muséum National d'Histoire Naturelle, Département Histoire de la Terre, UMR 5143 Paléobiodiversité et Paléoenvironnements, Case postale n°38, 57 rue Cuvier, 75225 PARIS Cedex 05, France ( email@example.com)
On the phylogenetic affinities of the pseudo-toothed birds (Aves, Odontopterygiformes).
A convention between the Muséum National d’Histoire Naturelle (France) and Moroccan authorities has led to the recent discovery of the first avian remains from the Ouled Abdoun Basin (Morocco). Fossil birds are Late Paleocene to Early Eocene in age and represent the oldest modern birds (Neornithes) from Africa.
The Ouled Abdoun avifauna is largely composed of pseudo-toothed birds, which are extinct large seabirds with a huge bill bearing tooth-like processes. The three species from the Ouled Abdoun are among the oldest representatives of this group. The first two taxa, Odontopteryx toliapica (2-3 m wingspan) and Dasornis londinensis (4 m wingspan), are also known from the Lower Eocene London Clay (England). The third one is a new genus and species that represents the smallest known pseudo-toothed bird (1.6 m wingspan).
The phylogenetic affinities of the pseudo-toothed birds have remained controversial. Some authors noted that they resemble both Procellariiformes (tubenoses) and Pelecaniformes (pelicans and allies), but assigned them to a distinct taxon, the Odontopterygiformes. In most recent studies, however, the pseudo-toothed birds are referred to the Pelecaniformes.
A cladistic analysis including the new Moroccan specimens has been performed to assess the phylogenetic position of the pseudo-toothed birds within Neognathae. A sister group relationship between pseudo-toothed birds (Odontopterygiformes) and waterfowls (Anseriformes) is strongly supported. A new hypothesis for the earliest divergences of the Neognathae is proposed: the landfowls (Galliformes) are sister to the remaining Neognathae. The latter taxon splits into Odontoanserae (Anseriformes plus Odontopterygiformes) and Neoaves (all others).
CNRS (UMR 5125), 16 cour du Liégat, 75013 Paris, France (firstname.lastname@example.org)
An early azhdarchid pterosaur from the Lower Cretaceous of eastern France.
In the 19th
century, phosphate nodules from the early Albian Sables Verts of the Argonne region (eastern Paris Basin) were intensively exploited for the production of fertiliser. In the course of this activity, fairly abundant vertebrate remains were recovered, belonging to fishes
, ichthyosaurs, plesiosaurs, crocodilians, dinosaurs and pterosaurs. Barrois (1875) and then Sauvage (1882) described a cervical vertebra from the Sables Verts which can be referred to an ornithocheiroid pterosaur. The purported pterosaur teeth reported by Barrois and Sauvage are not pterosaurian (they probably are fish teeth). An additional pterosaur cervical vertebra from the Sables Verts has recently been found in the palaeontological collection of the University of Paris. Its elongate centrum without lateral pleurocoels, its very low neural spine and the presence of a cylindrical bony tube (tuba neuralis), which enclosed the spinal cord, “hanging” inside the hollow centrum, indicate that it belongs to an azhdarchid. This Albian vertebra is one of the earliest well-ascertained records of the Azhdarchidae, and shows that the very peculiar construction of the cervical vertebrae typical of that family was acquired at an early stage of its evolutionary history.
Richard J. Butler1,2, Roger M. H. Smith3 & David B. Norman1
1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK
2Department of Palaeontology, The Natural History Museum, Cromwell Road, London, SW7 5BD, UK,( R.Butler@nhm.ac.uk)
3South African Museum (Iziko Museums of Cape Town), PO Box 61, Cape Town, 8000, South Africa
The first ornithischian dinosaur from the lower Elliot Formation (Late Triassic: ?Norian) of South Africa.
Ornithischia was a diverse and abundant clade of largely herbivorous dinosaurs that played an important role in Mesozoic ecosystems. Ornithischians split from their sister-taxon Saurischia during the Carnian, and some recent phylogenies imply significant ornithischian diversification prior to the Triassic-Jurassic boundary. Despite this, uncontroversial ornithischian remains are scarce in Upper Triassic sediments and are represented by fragmentary specimens only. Here we report the first ornithischian specimen (SAM-PK-K8025) from the lower Elliot Formation (Late Triassic: ?Norian) of South Africa. SAM-PK-K8025 comprises a disarticulated but closely associated and relatively complete postcranial skeleton with fragmentary skull elements and, as such, represents the most complete Triassic ornithischian yet discovered. Its anatomy closely resembles that of other basal ornithischians such as Lesothosaurus diagnosticus
, South Africa) and Scutellosaurus lawleri
(Early Jurassic, North America), suggesting that many key ornithischian synapomorphies were present by the latest Triassic. However, SAM-PK-K8025 differs from other basal ornithischians in a number of phylogenetically informative features, suggesting that it represents a new and distinct taxon. A phylogenetic analysis (51 taxa, 228 characters) positions SAM-PK-K8025 as the sister taxon to Genasauria, although basal ornithischian relationships are generally poorly supported. When calibrated to stratigraphy, the resulting phylogeny suggests that ornithischians radiated in diversity, abundance and geographical distribution across the Triassic-Jurassic boundary.
JENNIFER A. CLACK1, PER E. AHLBERG2. AND HENNING BLOM2
1University Museum of Zoology, Cambridge, UK, 2Evolutionary Organismal Biology, Uppsala, Sweden ( email@example.com,1 Per.Ahlberg@ebc.uu.se,2 Henning.Blom@ebc.uu.se 2)
Ontogeny of the humerus in Ichthyostega.
Specimens of Ichthyostega
discovered in 1998 on the south face of Celsius Bjerg are juvenile or sub-adults, with skull lengths only two-thirds of most other specimens. Three incomplete humeri from two sets of postcrania show distinct differences from those of larger specimens. Some more ‘fish-like’ characters may suggest an aquatic phase of life: shorter head, more oblique ventral ridge pierced by many foramina, head and entepicondyle separated by a broad open curve rather than a distinct angle, with the limits of the entepicondyle poorly differentiated. Juvenile characters include: poorly ossified ectepicondyle; relatively very large entepicondylar foramen. A feature of uncertain polarity is the broadly separated radial and ulnar facets. Recent work has suggested that an oblique course for the ventral ridge and numerus piercing foramina is characteristic of tetrapodomorph fish, found up to the level of Panderichthys
. In larger specimens of Ichthyostega
, the ventral ridge is low and runs at right angles to the long axis of the humerus: its proximal end approaches closer to the radial facet. The number of foramina is reduced
, and the epicondyles become more clearly defined, better ossified and more prominent. The latter are features more characteristic of adult limbed tetrapods. The contrast shows the juveniles to be distinctly more fish-like. An increasingly supportive role for the humerus is suggested, associated with emersion of the head and front part of the body, with a presumed increase in terrestrial capability. The transition appears to have occurred at a relatively late stage in the animal’s growth trajectory.
2, place Eugène Bataillon, Université de Montpellier 2, ISEM, UMR 5554 CNRS, 34095 Montpellier cedex 5 (firstname.lastname@example.org)
The ancestry of soft-shelled turtles debated.
Together with with the leatherback turtle, soft-shelled turtles (Trionychidae) are morphologically among the most divergent groups of living turtles. Their carapace lacks horny scutes and their snout usually consists in a long proboscis. Traditionnaly, systematists have nested Trionychidae within a larger group, the Trionychoidea, containing the Dermatemydidae, Kinosternidae, Trionychidae and Carettochelyidae. Recent phylogenetic molecular analyses have split the group into two independent clades, Trionychoidea and Kinosternoidea, and indicate that Trionychidae split before modern Cryptodira. This hypothesis is important because it could radically challenge the biogeographical scenario about the evolution of both groups. However most paleontologists, based on morphological cladistic evidence, are still using the term Trionychoidea in its former sense, precluding many alternative evolutionary hypotheses to be tested. In this short essay, I will present debated questions about the geographical origin and evolution of soft-shelled turtles, based on newly re-described and discovered fossils, emphasizing mostly the Asian fossil record, and recently published molecular phylogenies. The question whether fossil turtle systematists will use phylogenetic methods with more flexibility
, leaving away the agnosticism myth, to be in agreement with DNA evolution and paleogeographical occurrence will be debated.
GAËL CLÉMENT1 & MATT FRIEDMAN2
1Sub-Department of Evolutionary Organismal Biology, Department of Physiology and Developmental Biology, University of Uppsala, Sweden (email@example.com);
2Committee on Evolutionary Biology, University of Chicago, USA (firstname.lastname@example.org)
A Late Devonian lungfish assemblage from Belgium: environmental and biogeographical considerations.
The recently rediscovered site of Strud (Namur Province, Belgium) has yielded a diverse Famennian (late Devonian) biota. It includes miospores, large plants, arthropods and vertebrates (acanthodians, placoderms, actinopterygians and sarcopterygians). The latter are particularly common with abundant isolated remains of porolepiforms, dipnoans (or lungfishes), osteolepiforms, and rhizodontids. This locality has also yielded the lower jaw of an ichthyostegid tetrapod. Lungfishes are of special interest. At least four different taxa are present: a dipterid known by isolated tooth plates showing typical radiating ridges of dentine, the genus Oervigia known from a single, incomplete specimen, and the long-snouted lungfishes Soederberghia and Jarvikia , which are represented by isolated lower jaws and skull roofs. These dipnoans range from the small-sized Oervigia (about 5 cm) to the large-sized Soederberghia (more than 1 meter). The presence of lungfishes with tooth plates (crushing dentition) and with denticle-bearing plates (sucking dentition) shows that they exploited different trophic resources. Similar dipnoan assemblages were previously only known in the Late Famennian of East Greenland. This suggests close relations, most probably by hydrographic links, between the inland part (East Greenland) and the south margin (Belgium) of Euramerica during Famennian times. It is important to note that the East Greenland environment is supposed to be fluviatile whereas the Belgian environment is considered to be estuarine (brackish to freshwater).
Loïc Costeur1 & GERTRUD RÖSSNER2
1UMR CNRS 6112 Laboratoire de Planétologie et Géodynamique. Université de Nantes, France. (email@example.com); 2Department für Geo- und Umwelt-wissenschaften, Section Paläontologie- Ludwig-Maximilians University, Munich.
Quantitative estimate of the morphological variability in extant Moschus . Implications for the fossil moschids Dremotherium and Amphitragulus from the European Oligo-Miocene.
The taxonomy of the European fossil moschid genera Dremotherium
is still highly problematic especially when considered that both taxa are dominant components of the Late Oligocene and Early Miocene ungulate faunas (Costeur et al., 2004). 13 species have been described so far in these two genera based on different size classes and morphological characters of the fossil material (Sigogneau, 1968; Jehenne, 1987). Unfortunately no in-depth analysis of the natural variation in extant forms, in size and morphologies, has been done to date to try to validate the fossil taxa . A study of a large set of skulls and teeth of the extant genus Moschus
, the last representative of the moschid family living today in Asia, has been carried out to quantitatively estimate its natural variation. The first observations indicate that size as well as morphological variations are rather important in extant populations, in particular tooth size showing a variation ranging from 10 to 20% and tooth morphology with more or less marked characters on the upper molars and lower premolars all together already indicating that both fossil genera are probably part of the same taxon. Further work to be done will allow to better constrain the morphological variation at the species level and to propose a new taxonomical classification for the abundant fossil material.
Costeur, L., S. Legendre & G. Escarguel (2004). European large mammals palaeobiogeography and biodiversity during the Neogene. Palaeogeographic and climatic impacts. Revue de Paléobiologie, vol. spéc. 9: 99-109.
Jehenne, Y. (1985). Les ruminants primitifs du Paléogène et du Néogène inférieur de l'Ancien Monde: systématique, phylogénie, biostratigraphie. Thèse - Faculté des Sciences de l'Université de Poitiers: 288 p.
Sigogneau, D. (1968). Le genre Dremotherium (Cervoidea). Anatomie du crâne, denture et moulage endocrânien. Annales de Paléontologie, 54(1): 39-100.
PHILIP COX & NATHAN JEFFREY
Department of Human Anatomy & Cell Biology, University of Liverpool, Liverpool, UK (P.Cox@liverpool.ac.uk)
Are inner ear and extraocular muscle orientations invariant during primate development?
The vestibulo-ocular reflex (VOR) determines how all mammals interact with their environment during locomotion. The VOR system of compensatory ocular movements in response to stimulation of the kinetic labyrinth is highly complex and has been the focus of considerable research and contention for decades. Perhaps the simplest influence on the VOR is the spatial orientation of the planes of the semicircular canals relative to the planes of the paired extraocular muscles. However, despite its obvious importance, we know very little of this spatial arrangement except for in humans and a few laboratory species. Moreover, nothing is known about any ontogenetic changes in the relative orientations of the extraocular muscles and semicircular canals.
The morphologies of foetal specimens of Tarsius bancanus and Homo sapiens were examined using magnetic resonance (MR) images. Three-dimensional co-ordinate data were taken from the images and used to calculate angles between the planes of the extraocular muscles and the semicircular canals. It was shown that the relative orientations of the extraocular muscle pairs and the semicircular canals change during pre-natal development and, furthermore, that there is a tendency for the orientations of the muscles and canals to become more closely aligned with one another with increasing size. This contradicts the previously-held viewpoint that the planes of the canals and corresponding muscle pairs are in parallel and are fixed in their orientations (Simpson & Graf, 1981). It is thus demonstrated that there is a much greater degree of plasticity in the architecture of the VOR system than previously recognised.
Simpson, J. I. & Graf W. 1981. Eye-muscle geometry and compensatory eye movements in lateral-eyed and frontal-eyed animals. Ann. NY Acad. Sci. 374: 20-30
GILLES CUNY1, LIDE CHEN2, & XIAOFENG WANG 2
1 Geological Museum, University of Copenhagen, Øster Voldgade 5-7, 1350 Copenhagen K, Denmark (firstname.lastname@example.org); 2 Yichang Institute of Geology and Mineral Resources, Yichang 443003, China
The Shark Fauna from the Middle-Late Triassic of Guanling (Guizhou province, SW China).
Since 2002, a collaboration between The Yichang Institute of Geology and Mineral Resources, The Martin-Luther-Universität Halle-Wittenberg (Prof. G.H. Bachmann), the Muschelkalkmuseum of Ingelfingen (Dr. Hans Hangdorn), the University of Bonn (Prof. Martin Sander) and the Geological Museum in Copenhagen has focused on the study of the Middle-Late Triassic of the Guanling area (Guizhou Province, Southwest China). The most spectacular fossils include complete crinoid colonies and marine reptiles found in the Carnian Xiaowa Formation, but screen-washing of sediments from the Yangliujing (Anisian-Ladinian), Zhuganpo (Ladinian/Carnian) and Xiaowa (Carnian) Formations has also yielded various chondrichthyan ichthyoliths. It is these fossils that we present here. Teeth of Polyacrodus contrarius were found in the Ladinian/Carnian, as well as a tooth of ?Parvodus in the Anisian, and a tooth of an indeterminate elasmobranch, possibly with neoselachian affinity, in the Ladinian/Carnian. Dermal denticles similar to Arctacanthus are also relatively common in the Ladinian/Carnian interval. They are much smaller than the Permian Arctacanthus, and the structure of their root prevents them for being hybodont cephalic spines.
MARK EVANS1 & COLIN R. McHENRY2
1Natural Sciences Section, New Walk Museum, 53 New Walk, Leicester, LE1 7EA, United Kingdom (Mark.Evans@leicester.gov.uk); 2School of Environmental and Life Sciences, University of Newcastle, Callaghan NSW 2308, Australia (email@example.com)
A basket full of ribs: the anatomy of the trunk region in plesiosaurs.
Despite over 180 years of study and a number of virtually complete specimens, major questions remain concerning aspects of plesiosaur anatomy. The functional morphology of the trunk region is one of these. Most reconstructions assume that plesiosaurs lacked a sternum, but the Nicholls and Russell model argues the presence of a sternal basket based upon ontogenetic, functional and comparative phylogenetic evidence. Taphonomic and morphological evidence from a number of plesiosaur families is consistent with this model. A specimen representing a new taxon from the Pliensbachian of England corroborates this view.
This specimen also informs the current debate on where the boundary between the cervical and dorsal regions of the vertebral column should be placed, and whether the concept of intermediate “pectoral” vertebrae is either useful or necessary. Pectoral vertebrae are traditionally defined as those in which the rib facet is divided by the centrum-neural arch suture. It is here proposed that the dorsal series in plesiosaurs starts with the first vertebra to bear ribs with cupped distal ends, signifying involvement in the sternal basket, and connection to the sternum. In this particular case, this vertebra is the last of the traditional “pectoral” series. This shows that the concept of the pectoral series as a distinct region of the plesiosaur vertebral column is invalid.
However, the usefulness of this definition of the starting point of the dorsal series remains somewhat unsatisfactory, as it as it requires that a specimen displays a high degree of preservation and articulation.
SUSAN E. EVANS1 and YUAN WANG2
1Department of Anatomy & Developmental Biology, University College London, Gower Street, London, WC1E 6BT, England [firstname.lastname@example.org]; 2Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China [email@example.com]
Mesozoic lizards from China.
The Jehol Group of China is composed of three formations in ascending order: the Dabeigou Formation, the Yixian Formation and the Jiufotang Formation
, spanning a period from the Late Hauterivian to Aptian (131-120 Ma). Rocks of the Jehol Group are best exposed in western Liaoning and northern Hebei provinces, but the Xinminpu Group, Gansu Province, and the Qingshan Group, Shandong Province, may be lateral equivalents. Together, the Yixian and Jiufotang formations, and their equivalents, have produced numerous lizard specimens (Dalinghosaurus
), but, as yet, none have been recovered from the older Dabeigou Formation, leaving a gap in the early record.
The Daohugou Bed of Inner Mongolia and Liaoning (well represented at Daohugou, Ningcheng County, southeastern Inner Mongolia) predates the Jehol Group, although its age is controversial. While some have argued for a Middle or Late Jurassic age (based mainly on invertebrates), others regard the bed as younger (latest Jurassic or Early Cretaceous). The Daohugou locality has produced hundreds of well-preserved salamander remains (including a new species of the Jehol salamander Liaoxitriton ) as well as a few dinosaurs and pterosaurs, and a mammal, but has only recently yielded lizards. These are rare but, like the salamanders, they show exquisite soft tissue preservation. The new Daohugou specimens are the oldest lizards currently known from China and represent a significant addition to the emerging picture of lizard evolution in eastern Asia.
Julia M. Fahlke1 & Ellen Schulz2
1University of Bonn, Institute of Palaeontology, Nussallee 8, D-53115 Bonn, ( firstname.lastname@example.org)
2University of Hamburg, Zoological Institute and Museum, Martin-Luther-King-Platz 3, D-20146 Hamburg, (email@example.com)
Reconstruction of the diet in Central European Chalicotheriidae (Mammalia, Perissodactyla).
The Chalicotheriidae are large, claw-bearing perissodactyls. They are divided into two subfamilies, the Chalicotheriinae and the Schizotheriinae, distinguished by the more derived stage of the cheek dentition but more primitive postcranial anatomy of the latter group. 58 upper cheek teeth of three species representing both subfamilies (Metaschizotherium fraasi , Chalicotherium grande and C. goldfussi ) from 27 m
Middle and Late Miocene vertebrate localities of Southern Germany were analyzed with respect to their mesowear signatures. The localities are situated within the Upper Freshwater Molasse (MN5 to MN9), the Dinotheriensande (MN9), and on the karst plateau of the Franconian Alb (MN6). Mesowear signatures are interpreted as indicating a specific dietary regime and as such to reflect a habitat-driven signal of food availability. In the present study the two cervids Axis axis (chital) and Cervus duvauceli (swamp deer) are the extant reference species classified closest to all Chalicotheriidae investigated. We thus contradict the common assumption of chalicotheres being solely browsers and conclude a mixed feeding dietary regime with substantial components of abrasive food items. This observation is independent from the stratigraphic level. Since grasses were not very widespread before the end of the Miocene, another abrasive food component must have applied for the chalicotheres, such as Equisetum (horsetail), or fruit containing lignine and phytoliths. The resemblance in the diet of representatives of both Schizotheriinae and Chalicotheriinae contrasts with the different morphologies of their terminal phalanges. Thus the often proposed function of the claws in obtaining food must be reconsidered.
Dept. Geology, Leicester University and New Walk Museum, Leicester
Address for correspondence: 3 Chestnut Grove, Radcliffe on Trent, Nottingham NG12 1AH, UK (firstname.lastname@example.org)
A plesiosaur from the Pliensbachian of Lincoln.
The partial skeleton of a long-necked plesiosaur was donated to Lincoln Museum in 1906. Unusually for an historic specimen, it can be placed in a sound stratigraphical context, and be confidently dated as Pliensbachian. Although the specimen has been on display in Lincoln at various times, it is not recorded in the scientific literature. Its preparation and description have been undertaken as a PhD project.
Morphological evidence suggests a close relationship to the Toarcian genera Microcleidus and Occitanosaurus . Cladistic analyses of the plesiosauria place these, with “Plesiosaurus” brachypterygius , as part of a radiation of Lower Jurassic forms from within which the Upper Cretaceous Elasmosauridae are derived. However,
character-based support for this relationship is rather weak, and it involves also an interval of about 90 million years from which no related specimens are recorded.
An unusual feature of the specimen is that the spinal column is broken in the middle of the dorsal series, with the posterior portion displaced forward by about 50cm to lie parallel to the anterior portion. Preparation has revealed possible tooth marks in the vertebral column at the base of the neck, and twisting of the of dorsal vertebrae anterior to the break. The presence of ribs which cannot be matched to specific centra suggests that two or three vertebrae are missing from the mid-dorsal region. It is suggested that this is evidence that the animal was attacked by a large and powerful predator, possibly a Rhomaleosaurid pliosaur.
EMMANUEL GHEERBRANT1, HENRI CAPPETTA2, MBAREK AMAGHZAZ3, BAADI BOUYA3
1UMR 5143, CP38, Dpt Earth History, MNHN, 8 rue Buffon, F-75005 Paris, France (email@example.com)
2UMR 5554 "Institut des Sciences de l'Evolution", Université de Montpellier II, Cc 064, Place Eugène Bataillon, 34095 Montpellier Cedex 5, France
3OCP group, DEK/DIR, Geological Survey, Khouribga, Morocco
The mammals from the late Paleocene and early Eocene of the Ouled Abdoun Basin, Morocco: A review and the perspectives.
The Ouled Abdoun epicontinental basin (Morocco) is renowned for its rich Maastrichtian-Ypresian marine vertebrate fauna. In 1996, the unexpected first discovery of an Ypresian mammal, the earliest known proboscidean Phosphatherium escuilliei,
opened new major perspectives for the knowledge of the early radiation of African placentals
, and especially of African ungulates.
Since then, a new significant mammal material has been discovered in several Paleogene Ouled Abdoun quarries, mostly by local people searching for fossils to sell. The fossils (incl. more or less complete skulls) are well preserved and meaningful. However, they are very scarce, all being isolated discoveries. The absence of concentration of continental remains relates to a peculiar taphonomy of floated-bodies dispersed under conditions of low hydrodynamic energy along the eastern basin near the shores. All Phosphatherium
fossils come from the Grand Daoui quarries (NE area), from an early Ypresian bone-bed at the beginning of the Eocene phosphate sequence (field observations). Several other mammal taxa have been discovered in Grand Daoui quarries, such as the large proboscidean Daouitherium
, a new primitive hyracoidean close to Seggeurius
, a new hyaenodontid creodont, the two “condylarths” Ocepeia
, and an indeterminate ungulate. The early Ypresian age of Phosphatherium
is supported by the associated selachian fauna. However new discoveries at Sidi Chennane and Meraa El Arech suggest that Ocepeia
belong to a distinct Thanetian phosphate level. These new sites stress again the importance of the Ouled Abdoun phosphate series for the knowledge of the early African placental history.
Pascal Godefroit1, Shulin Hai 2, Tinghai Yu 2, and Pascaline Lauters1
1Institut royal des Sciences naturelles de Belgique, Département de Paléontologie, rue Vautier, 29, B- 1 000 Bruxelles, firstname.lastname@example.org and email@example.com.
2Geological Museum of Heilongjiang, Xiangfang District, Harbin, P.R. China, firstname.lastname@example.org.
A new latest Cretaceous dinosaur locality in northeastern China.
A new dinosaur locality has been discovered in the Yuliangze Formation (late Maastrichtian) of Wulaga (Heilongjiang Province, China). More than 500 hadrosaurid bones
, together with well-preserved skin impressions, have been unearthed from a continuous bonebed in a diamictite layer. This facies is interpreted as a sediment gravity flow deposit. The Wulaga quarry can be regarded as a monodominant bonebed: more than 80% of the bones belong to a new genus of lambeosaurine hadrosaurid. Phylogenetic analysis shows that this new taxon is a derived lambeosaurine that forms a monophyletic group with the corythosaur and parasauroloph clades. Besides lambeosaurine fossils, isolated bones display typical hadrosaurine morphology and are also referred to a new taxon. This taxon displays a series of plesiomorphic characters and phylogenetic analysis indicates that it
would be the most basal hadrosaurine known to date. It suggests that hadrosaurines, and thus hadrosaurids, would have had an Asian origin, which implies a relatively long ghost lineage, of approximately 13 my, for basal hadrosaurines in Asia. The size-frequency distribution of different types of bones collected in the Wulaga bonebed suggests that a sudden event caused the non-selective mass mortality of the lambeosaurine population, regardless of the age, size and robustness of the individuals.
Ursula B. GÖHLICH1 & Luis M. CHIAPPE2
1Department for Geo- and Environmental Sciences, Section Palaeontology, University Munich, Richard-Wagner Str. 10, D-80333 Munich, GERMANY. (email@example.com).
2The Dinosaur Institute, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA. (firstname.lastname@example.org)
Juravenator – a new theropod dinosaur from the Upper Jurassic of Southern Germany.
Excavations directed by the Jura-Museum Eichstätt during the late 1990s in the silicified Upper Jurassic limestones of Schamhaupten (Franconian Alb, Bavaria, Southern Germany) yielded the new, small-sized theropod dinosaur Juravenator starki
. The almost complete, articulated skeleton of Juravenator
, is the best preserved non-avian theropod in Europe, regarding its completeness as well as its soft tissue preservation.
is the second dinosaur ever discovered in the famous Jurassic limestones of the Solnhofen archipelago in Southern Germany – the first discovery was the celebrated Compsognathus
some 150 years ago. However, Compsognathus
, as well as a number of skeletons of the most ancient bird Archaeopteryx
, come from the Lithographic Plattenkalk (Solnhofen Limestones, Lower Tithonian, Malm zeta), a stratigraphic unit slightly younger than the 151-million-year-old Silicified Plattenkalk of Schamhaupten (uppermost Kimmeridgian to Tithonian, Malm epsilon – zeta 1).
Several osteological characters support the assignation of Juravenator to Coelurosauria and other anatomical features place it phylogenetically together with Compsognathus within compsognathids.
Particularly important is the exquisite preservation of portions of soft tissue, which are best observed along the tail and somewhat also along the lower legs. Integumentary impressions in the proximal portion of the tail show a scaly, tuberculated skin; additionally, UV-light illumination visualizes mineralized remains of soft parts along the tail and lower legs. Noteworthy, the soft tissue does not show any evidence of feathers or feather-like integumentary appendages, structures well-known among compsognathids (Sinosauropteryx ) and several other non-avian coelurosaurs (e.g. Caudipteryx , Microraptor, Sinornithosaurus ). The lack of feather-like integumentary coverings in Juravenator complicates current understanding of the evolution of feathers among the dinosaurian predecessors of birds.
South Dakota School of Mines and technology, Dept. of geology and geophysic, 501 East St. Joseph Street, Rapid City, SD, USA (email@example.com)
Dinosaur Eggs and Endothermy in Deinonychosaurians: “In ovo veritas ”.
Endothermy in non-avian dinosaurs cannot be answered by first level observations but could be inferred from oological observations. Evolutionary trends in eggs, eggshell microstructures, clutches, and nests shapes, unlike bone histology and presence of feathers, provide a powerful proxy that suggests that troodontids, a group of deinonychosaurian theropods found at high latitudes, covered with feathers in Chinese Lagerstätten, and fossilized in a death pose identical to an avian sleeping posture, might have been endothermic.
Re-interpretation of four dubious characters among the mosaic of oological and nesting characters displayed by D . antirrhopus yields interesting results by placing this dromaeosaurid closer to troodontids than oviraptorids, a topology that mirrors the current skeletal hypothesis. This topology is mostly supported by 1) the presence of an egg found outside of the body cavity and apposed to the outer surface of gastralia and 2) the aspect and size of two truncated polar sections in respect to the preserved length of its equatorial region. This observation not only revives the interesting debate of missing or partial data in analyses of fossils and the methodology to deal with such issues but also suggests that D.antirrhopus would have been endothermic. This hypothesis stands although there are missing data in the oological characters of D. antirrhopus and the observed oological features are a mosaic of characters shared by oviraptorosaurids and troodontids. In conclusion, endothermy would be synapomorphic for Deinonychosaurians and, in addition to other characters that were long-held to be exclusively avian, endothermy would have predated the rise of birds.
Residence Les Acacias, Entrée Nr. 4, Val St. André, 13100 Aix en Provence, France
Functional morphology of the skull musculature and the limbs of two German plesiosauroids and their implications on predation.
Reconstructions of the cranial musculature of the two plesiosauroid genera Hydrorion brachypterygius
and Seeleyosaurus guilelmiimperatoris
from the Liassic Posidonia shale show similarities in the general arrangement of muscles. However, differences in functional anatomy do exist and are probably related to the mode of predation. The musculature of Hydrorion
was capable of exerting higher bite forces than that of Seeleyosaurus
, whereas in the latter genus the muscles achieved higher speeds for closing the jaws. While the postcranial of the two taxa is remarkable alike, the limbs show distinct differences in length, which leads to divergent swimming abilities. The limb aspect ratio of both genera was calculated, and shows low to moderate values for Hydrorion
, indicating a high manoeuvrability, and relatively high values for Seeleyosaurus
, which denotes efficiency.
These differences in the feeding apparatus and the locomotion, in comparison with the excellent and abundant fossil content of the Posidonia shale, allows to assign possible prey to each taxon. Hydrorion probably fed on Leptolepis , a sprat-like swarm fish common in certain levels of the Posidonia shale, whereas Seeleyosaurus preyed upon coleoids.
Department of Palaeontology, Natural History Museum, Cromwell Road, London, SW7 5BD, UK. (firstname.lastname@example.org)
Bipedal browsing adaptations of the Late Eocene-earliest Oligocene tylopod Anoplotherium (Artiodactyla, Mammalia).
The first well-preserved, partial associated skeleton of Anoplotherium latipes is described from the UK earliest Oligocene. Tibia, femur, ulna and cervical vertebrae are more completely known for the genus than previously. A. latipes and related species and genera are interpreted as facultatively bipedal, extended-limb, high browsers, based especially on the following: pelvis with flared ilia and long pubic symphysis; medially bowed tibiae shorter than femur; trunk vertebrae enlarging caudally; extensive attachment for supraspinous and deltoid muscles for raising the forelimbs; long muscular tail for balance; and large hind-foot processes for attachment of suspensory ligaments. The adaptations are closest to those of ground sloths, although are not exactly like any other bipedal browser living or extinct in combining long tail, unclawed unguals and relatively low intermembral index. This is probably because Anoplotherium had evolved hooves but retained a primitively long tail. Emphasis was therefore on maintaining an erect stance without forelimb support. Having only toe-number differences, A. commune and A. latipes may have been sexual dimorphs. The large Anoplotherium species would have been able to browse 2-3 metres above the ground without competition from other contemporaneous European terrestrial mammals. Bipedal high browsing represents an adaptation previously unrecognised in European Eocene communities
MNHN, Laboratoire de Paléontologie, 8 rue Buffon, 75005 Paris (