Dinosaurs and other tetrapods in an Early Cretaceous bauxite-filled fissure, northwestern Romania

The bauxite mine at Cornet near Oradea in northwestern Romania produced thousands of bones in an excavation in 1978, mainly from ornithopod dinosaurs and rarer pterosaurs. Bird specimens reported previously from this fauna are equivocal. The fossils are disarticulated bones in good condition which occur highly concentrated in lenses within bauxite clays, which are dated as Berriasian (earliest Cretaceous). The bauxite represents detrital material washed into deep fissures and caves formed within a karst of uplifted Tithonian (latest Jurassic) marine limestones. The bones are generally uniform in size and shape, and they are abraded, evidence for considerable transport and for winnowing of the deposit. The area was one of several islands on the northern shore of Tethys, and it was inundated by the sea later in the Early Cretaceous. There is evidence for insular adaptations in the dinosaur faunas. The ornithopod dinosaurs may include several taxa, but they are smaller on average than an assemblage of typical Wealden ornithopods, perhaps because of dwarfing on the island. In addition, sauropods are absent and theropods are barely represented in the fauna. The fauna is geographically significant since it shows relationships with western Europe and with Asia.     

Dinosaurs

Wild Cactus. Photos by George H. H. Huey, text by Rose Houk. New York: Artisan, 1996. $25. ISBN 1-885183-20-8. Reviewed by John W. McLure.

Exploring with the Microscope. Werner Nactigall. New York: Sterling Publishing Company, 1995. 160 pp. $19.95 (hardcover). ISBN 0-8069-0066-1. Reviewed by Robert G. Hoehn.

The Encyclopedia of Snakes. Chris Mattison. New York: Facts On File, 1995. 256 pp. $35.00 (hardcover). ISBN 0-8160-3072-3. Reviewed by Carl Gans.

The Friendly Guide to the Universe. Nancy Hathaway. New York: Penguin, 1995. 462 pp. $13.95 (paperback). ISBN 0-14-015381-0. Reviewed by Lawrence A. Marschall.

One Small Square: Woods. Donald M. Silver, illustrations by Patricia J. Wynne. New York: W. H. Freeman and Company, 1995. 48 pp. $14.95 (hardcover). ISBN 0-7167-6610-8. Reviewed by Frances B. Spuler.

Naturalists, Conservationists, and Environmentalists. Eileen Lucas. New York: Facts On File, 1996. 150 pp. $16.95 (hardcover). ISBN 0-8160-2919-0. Reviewed by Clarence J. Murphy.

Astronomy for All Ages. Philip Harrington and Edward Pascuzzi. Old Saybrook, Conn.: Globe Pequot Press, 1994. 210 pp. $17.95 (paperback). ISBN 1-56440-388-2. Reviewed by Kristine Larsen.

Intermediate Science through Children's Literature. Carol M. Butzow and John W. Butzow. Englewood, Colo.: Teacher Ideas Press, 1994. 194 pp. ISBN 0-87287-946-1. Reviewed by Jacqueline V. Mallinson.     

Dinosaurs of France

The French dinosaur record is one of the most extensive in Europe; it ranges stratigraphically from the Late Triassic to the Latest Cretaceous. All major clades of dinosaurs but marginocephalians are known. About 20 species are based on significant material; the theropods are the best represented. Most of these taxa have been described or revised in recent years. Important specimens have been discovered in the Late Triassic of eastern France, the Middle Jurassic of Normandy, and the Late Cretaceous of Provence and Languedoc. The ichnological record is good for the Late Triassic-Early Jurassic, and the Late Cretaceous egg sites are among the richest in the world. To cite this article: R. Allain, X.P. Suberbiola, Palevol 2 (2003) 27–44.     

Dinosaurs of Portugal

A synthesis on the state of art on dinosaur knowledge in Portugal is presented. The following genera have been recognized: Ceratosaurus, Torvosaurus, Lourinhanosaurus, Allosaurus, cf. Compsognathus, Stokesosaurus, cf. Richardoestesia, cf. Archaeopteryx, Euronychodon, cf. Paronychodon, Dinheirosaurus, Lourinhasaurus, Lusotitan, cf. Pleurocoelus, Lusitanosaurus, Dacentrurus, Dracopelta, Phyllodon, Hypsilophodon, Alocodon, Trimucrodon, Draconyx, Iguanodon, and Taveirosaurus. Most are from Late Jurassic localities at the Lourinhã area and Guimarota. A new genus, Lusotitan, is here raised to include the Late Jurassic ‘Brachiosaurus’ atalaiensis. Lower Cretaceous until Cenomanian material is scarce, except for dinosaur footprints. An interesting Late-Cretaceous, mostly small dinosaur association has been collected between Aveiro and Taveiro. To cite this article: M.T. Antunes, O. Mateus, C. R. Palevol 2 (2003) 77–95.     

Dinosaurs of Switzerland

Until 1960, the record of dinosaurs was rather poor in Switzerland. Between 1960 and 1980, several new localities with plateosaurid remains as well as prosauropod and theropod tracks were found in Late Triassic sabkha and floodplain environments. The discovery of large surfaces with sauropod tracks in the Late Jurassic of the Jura Mountains in 1987 triggered a stream of new data. More than 20 new localities with tracks from both sauropod and theropod dinosaurs in different stratigraphic levels have been found since then. The latest discoveries include trackways of iguanodontids from the Early Cretaceous of the central Swiss Alps and a large Late Jurassic surface with trackways of small sauropods in the northernmost part of the Jura Mountains. The best skeletal record comes from the Late Triassic, with scattered data from the Late Jurassic. The track and trackway record appears to be best in the Late Jurassic. To cite this article: C.A. Meyer, B. Thüring, C. R. Palevol 2 (2003) 103–117.     

恐龙大地

这组照片全部是在1995年至1998年进行中日蒙三国蒙古高原恐龙考察时拍摄的,包括我国内蒙地区和蒙古国的南部及西部地区,这里曾经被称作“中亚细亚”,曾经植被丰富,气候湿润,曾经被众多的恐龙统治,但是现在却变成了人烟稀少的戈壁地区,地貌复杂,景色壮观。     

我国的恐龙

我国的恐龙分为早、中、晚三个不同时期的类群。介绍了从早侏罗世到晚白垩世,我国发现的主要恐龙化石和分布,阐述了它们之间的关系、发展和绝灭。     

Dinosaurs for everyone

The Complete Dinosaur edited by James O. Farlow and Michael K. Brett-Williams Indiana University Press (UK: Open University Press), 1997. ￡40.50/$59.95 hbk (752 pages) ISBN 0 253 33349 0.     

First Dinosaurs from Saudi Arabia

Dinosaur remains from the Arabian subcontinent are exceedingly rare, and those that have been documented manifest indeterminate affinities. Consequently the discovery of a small, but diagnostic, accumulation of elements from Campanian-Maastrichtian (∼75 Ma) deposits in northwestern Saudi Arabia is significant because it constitutes the first taxonomically identifiable dinosaur material described from the Arabian Peninsula. The fossils include a series of possible lithostrotian titanosaur caudal vertebrae, and some isolated theropod marginal teeth that share unique character states and metric parameters (analyzed using multivariate statistical methods) with derived abelisaurids – this is the first justifiable example of a non-avian carnivorous dinosaur clade from Arabia. The recognition of titanosaurians and abelisaurids from Saudi Arabia extends the palaeogeographical range of these groups along the entire northern Gondwanan margin during the latest Cretaceous. Moreover, given the extreme paucity of coeval occurrences elsewhere, the Saudi Arabian fossils provide a tantalizing glimpse into dinosaurian assemblage diversity within the region.     

Body Size Distribution of the Dinosaurs

The distribution of species body size is critically important for determining resource use within a group or clade. It is widely known that non-avian dinosaurs were the largest creatures to roam the Earth. There is, however, little understanding of how maximum species body size was distributed among the dinosaurs. Do they share a similar distribution to modern day vertebrate groups in spite of their large size, or did they exhibit fundamentally different distributions due to unique evolutionary pressures and adaptations? Here, we address this question by comparing the distribution of maximum species body size for dinosaurs to an extensive set of extant and extinct vertebrate groups. We also examine the body size distribution of dinosaurs by various sub-groups, time periods and formations. We find that dinosaurs exhibit a strong skew towards larger species, in direct contrast to modern day vertebrates. This pattern is not solely an artefact of bias in the fossil record, as demonstrated by contrasting distributions in two major extinct groups and supports the hypothesis that dinosaurs exhibited a fundamentally different life history strategy to other terrestrial vertebrates. A disparity in the size distribution of the herbivorous Ornithischia and Sauropodomorpha and the largely carnivorous Theropoda suggests that this pattern may have been a product of a divergence in evolutionary strategies: herbivorous dinosaurs rapidly evolved large size to escape predation by carnivores and maximise digestive efficiency; carnivores had sufficient resources among juvenile dinosaurs and non-dinosaurian prey to achieve optimal success at smaller body size.     

Cockroaches Probably Cleaned Up after Dinosaurs

Dinosaurs undoubtedly produced huge quantities of excrements. But who cleaned up after them? Dung beetles and flies with rapid development were rare during most of the Mesozoic. Candidates for these duties are extinct cockroaches (Blattulidae), whose temporal range is associated with herbivorous dinosaurs. An opportunity to test this hypothesis arises from coprolites to some extent extruded from an immature cockroach preserved in the amber of Lebanon, studied using synchrotron X-ray microtomography. 1.06% of their volume is filled by particles of wood with smooth edges, in which size distribution directly supports their external pre-digestion. Because fungal pre-processing can be excluded based on the presence of large particles (combined with small total amount of wood) and absence of damages on wood, the likely source of wood are herbivore feces. Smaller particles were broken down biochemically in the cockroach hind gut, which indicates that the recent lignin-decomposing termite and cockroach endosymbionts might have been transferred to the cockroach gut upon feeding on dinosaur feces.     

Dinosaurs and the Cretaceous Terrestrial Revolution

The observed diversity of dinosaurs reached its highest peak during the mid- and Late Cretaceous, the 50 Myr that preceded their extinction, and yet this explosion of dinosaur diversity may be explained largely by sampling bias. It has long been debated whether dinosaurs were part of the Cretaceous Terrestrial Revolution (KTR), from 125-80 Myr ago, when flowering plants, herbivorous and social insects, squamates, birds and mammals all underwent a rapid expansion. Although an apparent explosion of dinosaur diversity occurred in the mid-Cretaceous, coinciding with the emergence of new groups (e.g. neoceratopsians, ankylosaurid ankylosaurs, hadrosaurids and pachycephalosaurs), results from the first quantitative study of diversification applied to a new supertree of dinosaurs show that this apparent burst in dinosaurian diversity in the last 18 Myr of the Cretaceous is a sampling artefact. Indeed, major diversification shifts occurred largely in the first one-third of the group's history. Despite the appearance of new clades of medium to large herbivores and carnivores later in dinosaur history, these new originations do not correspond to significant diversification shifts. Instead, the overall geometry of the Cretaceous part of the dinosaur tree does not depart from the null hypothesis of an equal rates model of lineage branching. Furthermore, we conclude that dinosaurs did not experience a progressive decline at the end of the Cretaceous, nor was their evolution driven directly by the KTR.