A new Semionotid (Actinopterygii,Neopterygii) from the Late Jurassic–Early Cretaceous of Thailand

A new semionotid fish, Lepidotes buddhabutrensis n. sp., is described from the continental Late Jurassic–Early Cretaceous Phu Kradung Formation, Phu Nam Jun, Kalasin Province. L. buddhabutrensis is characterized notably by the pattern of its cheek bones, by its short preorbital region, and by its numerous and well-developed premaxillary teeth. L. buddhabutrensis is provisionally placed in the genus Lepidotes; it shares, however, derived characters with other semionotids, such as Araripelepidotes and Pliodetes. To cite this article: L. Cavin et al., C. R. Palevol 2 (2003).     

Plants of Leptostrobus Heer （Czekanowskiales） from the Early Cretaceous and Late Triassic of China, with Discussion of the Genus

Investigation of the Mesozoic seed plant Leptostrobus Heer from the Yangcaogou Formation of the Late Triassic and the Yixian Formation of the Early Cretaceous, Liaoning Province, China, provides new Insight Into Its general morphology and geographical distribution. The materials of L. cancer from the Yixian Formation described herein are later than all the past findings of this species and add to the record of L. cancer during the Early Cretaceous. Based on well-preserved specimens, the specific diagnosis Is slightly emended and the reconstructlon of L. cancer Is perfected. The materials from the Yangcaogou Formation of the Late Triassic are placed in L. spheericus, in addition, we review the history of investigation of the genus Leptostrobus since its establishment in 1876 and discuss the main characteristics of each species.     

On the history of Early—Middle Pleistocene mammal faunas of the Central Balkans

Based on the study of the Trlica faunas (Montenegro), the paleozoogeographical aspects of the history of faunas of the Central Balkans and Europe in the late Early Pleistocene and beginning of the Middle Pleistocene (1.8–0.4 Ma) are analyzed.     

Crayfish burrows from Late Jurassic–Late Cretaceous continental deposits of Patagonia: Argentina. Their palaeoecological,palaeoclimatic and palaeobiogeographical significance

The trace fossil, Loloichnus baqueroensis igen. and isp. nov., from Late Jurassic–Late Cretaceous continental deposits of Patagonia, Argentina, includes thickly lined, mostly passively-filled, and Y-branched burrows. Other important features of this ichnofossil are the inner surface texture of lining showing transversal, elongated, and adjacent grooves, and less commonly, the pelletal filling of burrows. L. baqueroensis is recorded from the Bajo Grande, Bajo Tigre, Punta del Barco, and Laguna Palacios Formations, which were deposited in different volcaniclastic environments of the Deseado Massif and San Jorge Basin geological provinces, respectively. The described burrows are found in many levels of palaeosols developed in reworked piroclastic deposits, where they are the main component of the ichnofabrics, in association with meniscate and thinly lined burrows and a diffuse and complex boxwork of small diameter burrows. Root traces are also present, and in many cases, occur inside L. baqueroensis. Considering general morphology, surface texture, filling types, palaeoenvironments in which they occur, and comparisons with extant and fossil decapod burrows, the likely trace makers of L. baqueroensis were crayfishes (Decapoda: Astacidea), probably Parastacidae. The producers of L. baqueroensis inhabited soils, where their burrows probably reached the water table, and contained roots that were used for feeding. Considering climatic preferences of extant parastacids, it is proposed a temperate climate for central Patagonia during the deposition of the studied units. The widespread presence of crayfishes during Late Jurassic–Late Cretaceous times in central Patagonia, supports the monophyletic origin of this group during the Triassic, and suggests that the present restricted geographic distribution in southern South America is a relict of a broader one.     

Late Jurassic ichthyosaurs from the Neuquén Basin,Argentina

Late Jurassic ichthyosaurs are well represented in the Tithonian of the Neuquén Basin, in northwestern Patagonia, Argentina. Most of the ichthyosaur material from the Neuquén Basin was originally identified as Ophthalmosaurus. Recently, the new ichthyosaur genus Caypullisaurus was described, based on an almost complete mature specimen from Cerro Lotena. Some material previously referred to Ophlhalmosaurus has been referred to the new genus. However, both genera are present in the Tithonian of the Neuquén Basin. The discovery of an articulated forefin in Cajón de Almanza (near Loncopue, Neuquén) confirms the presence of Ophthalmosaurus in the uppermost Tithonian of the Neuquén Basin.     

“South American” Marsupials from the Late Cretaceous of North America and the Origin of Marsupial Cohorts

Newly described marsupial specimens of Judithian (late Campanian) and Lancian (Maastrichtian) age in the western interior of North America (Wyoming to Alberta) have dental morphologies consistent with those expected in comparably aged sediments in South America (yet to be found). Three new Lancian species are referable to the didelphimorphian Herpetotheriidae, which suggests that the ameridelphian radiation was well under way by this time. The presence of a polydolopimorphian from Lancian deposits with a relatively plesiomorphic dental morphology and an additional polydolopimorphian taxon from Judithian deposits with a more derived molar form indicate that this lineage of typically South American marsupials was diversifying in the Late Cretaceous of North America. This study indicates that typical South American lineages (e.g. didelphimorphians and polydolopimorphians) are not the result of North American peradectian progenitors dispersing into South America at the end of the Cretaceous (Lancian), or at the beginning of the Paleocene (Puercan), and giving rise to the ameridelphian marsupials. Instead, these lineages, and predictably others as well, had their origins in North America (probably in more southerly latitudes) and then dispersed into South America by the end of the Cretaceous. Geophysical evidence concerning the connections between North and South America in the Late Cretaceous is summarized as to the potential for overland mammalian dispersal between these places at those times. Paleoclimatic reconstructions are considered, as is the dispersal history of hadrosaurine dinosaurs and boid snakes, as to their contribution to an appraisal of mammalian dispersals in the Late Cretaceous. In addition, we present a revision of the South American component of the Marsupialia. One major outcome of this process is that the Polydolopimorphia is placed as Supercohort Marsupialia incertae sedis because no characteristics currently known from this clade securely place it within one of the three named marsupial cohorts.     

“South American” Marsupials from the Late Cretaceous of North America and the Origin of Marsupial Cohorts

Newly described marsupial specimens of Judithian (late Campanian) and Lancian (Maastrichtian) age in the western interior of North America (Wyoming to Alberta) have dental morphologies consistent with those expected in comparably aged sediments in South America (yet to be found). Three new Lancian species are referable to the didelphimorphian Herpetotheriidae, which suggests that the ameridelphian radiation was well under way by this time. The presence of a polydolopimorphian from Lancian deposits with a relatively plesiomorphic dental morphology and an additional polydolopimorphian taxon from Judithian deposits with a more derived molar form indicate that this lineage of typically South American marsupials was diversifying in the Late Cretaceous of North America. This study indicates that typical South American lineages (e.g. didelphimorphians and polydolopimorphians) are not the result of North American peradectian progenitors dispersing into South America at the end of the Cretaceous (Lancian), or at the beginning of the Paleocene (Puercan), and giving rise to the ameridelphian marsupials. Instead, these lineages, and predictably others as well, had their origins in North America (probably in more southerly latitudes) and then dispersed into South America by the end of the Cretaceous. Geophysical evidence concerning the connections between North and South America in the Late Cretaceous is summarized as to the potential for overland mammalian dispersal between these places at those times. Paleoclimatic reconstructions are considered, as is the dispersal history of hadrosaurine dinosaurs and boid snakes, as to their contribution to an appraisal of mammalian dispersals in the Late Cretaceous. In addition, we present a revision of the South American component of the Marsupialia. One major outcome of this process is that the Polydolopimorphia is placed as Supercohort Marsupialia incertae sedis because no characteristics currently known from this clade securely place it within one of the three named marsupial cohorts. This article contains corrections to the text and a new Figure 11 not incorporated in the originally published version in Vol. 11, Nos. 3/4. For purposes of future citation, the present version (Vol. 12 and Nos. 3/4) should be used.     

On Late Jurassic–Early Cretaceous oysters of the genus <Emphasis Type="Italic">Deltoideum</Emphasis> Rollier (Bivalvia,Ostreoidea) from Siberia

Morphology, palaeoecology, and phylogeny of oysters of the genus Deltoideum Rollier from the Upper Jurassic and Lower Cretaceous deposits of Siberia are discussed. The diagnosis and composition of the genus are revised. A new endemic subgenus, Boreiodeltoideum subgen. nov., of the genus Deltoideum is described. This subgenus includes two species, D. (B.) praeanabarensis (Zakharov) and D. (B.) anabarensis (Bodylevsky).     

New ommatids from the Late Jurassic of western Liaoning, China （Coleoptera： Archostemata）

A new genus Amblomma gen. nov. of fossil beetles is erected and can be assignedto the family Ommatidae because its two procoxal cavities are contiguous and the articulations of the abdominal ventrites are abutting. The new genus is similar to Zygadenia Handlirsch, 1906 (=Notocupes Ponomarenko, 1964), Tetraphalerus Waterhouse, 1901,Rhobdocupes Ponomarenko, 1966 and Sinocupes Lin, 1976, but can be distinguished from other genera according to the following characters: the second segment of antennae is shorterthan the third one in length; the posterior tarsi with the basal segment is obviously shorter than the three following taken together in length; the antennae reach the posterior ridge of prothroax in length, and the sides of the prothroax with serrulate margin. Four new species of the new genus are described and figured: Amblomma psilata gen. et sp. nov., Amblomma rudis gen. et sp. nov., Amblomma epicharis gen. et sp. nov., and Amblomma stabilis gen. etsp. nov. A key to species within this new genus is provided. All the specimens are collected from the Late Jurassic Yixian Formation of western Liaoning and are now housed in the College of Life Science, Capital Normal University, Beijing, China.     

First Record of Theropod and Ornithopod Tracks and Detailed Description of Sauropod Trackways from the Tacuarembó Formation (Late Jurassic-?Early Cretaceous) of Uruguay

The record of dinosaur tracks and trackways from the Tacuarembó Formation (Late Jurassic-?Early Cretaceous) is described in detail: two trackways and four isolated tracks. Ichnites are preserved in sandstones of interdune facies of the Batoví (lower) Member. The interpretation herein presented indicates a sauropod affinity of the trackways, while the isolated prints are considered to have been made by an ornithopod and small theropods. The fossil record for this formation was primarily integrated by fresh-water organisms. The presence of new groups (sauropods and ornithopods) has specially contributed to the reconstruction of the terrestrial fauna, represented up until this time only by theropods.     

Illicioxylon, an Element of Gondwanan Polar Forests? Late Cretaceous and Early Tertiary Woods of Antarctica

The Late Cretaceous and early Tertiary sediments from the northernPeninsula region of Antarctica yield a rich assemblage of fossilwood with well preserved anatomy. Wood specimens of a previouslyrecognized morphotype are described. The woods are characterizedby diffuse porous wood, mainly solitary vessels with long scalariformperforation plates, scalariform and opposite vessel-ray pitting,generally uniseriate and biseriate heterogeneous rays, and tracheidswith obvious uniseriate, circulate, bordered pits. These fossilspecimens show greatest anatomical similarity to the organ genusIllicioxylon Gottwald and extant members of the Illiciaceae.The occurrence of illiciaceous-like wood in Gondwana suggeststhat the distribution of this family may have been more widespreadin the geological past and that a relatively warm temperateclimate prevailed over the northern Peninsula region of Antarcticaduring the Late Cretaceous and early Cenozoic. Copyright 2000Annals of Botany Company Fossil, wood, Illiciaceae, Illicioxylon, Illicium, Cretaceous, Tertiary, Gondwana, Antarctica     

The fossil record of Cunoniaceae: new evidence from Late Cretaceous wood of Antarctica?

Fossil angiosperm wood from Upper Cretaceous sediments of Livingston Island and James Ross Island in the northern Antarctic Peninsula region is identified as having the combination of anatomical characters most similar to modern Cunoniaceae. The material is characterised by predominantly solitary vessels, opposite to scalariform intervessel pitting, scalariform perforation plates, heterocellular multiseriate and homocellular uniseriate rays, diffuse axial parenchyma. Anatomically, the specimens conform most closely to the fossil organ genus Weinmannioxylon Petriella which has been placed within the Cunoniaceae. The presence of Weinmannioxylon in Late Cretaceous sediments suggests that taxa within or stem taxa to the Cunoniaceae might have been a notable component of the forest vegetation that covered the Antarctic Peninsula during the Late Mesozoic and may therefore represent the earliest record of this family.     

Two new theropod egg sites from the Late Jurassic Lourinhã Formation,Portugal

Two new Late Jurassic (uppermost Late Kimmeridgian) dinosaur eggshell sites are described, Casal da Rola and Porto das Barcas, both near Lourinhã, central-west Portugal. Casal da Rola yields eggshells with an obliquiprismatic morphotype comparable to those from a nest with the associated fossil embryos from Paimogo, tentatively assigned to the theropod Lourinhanosaurus antunesi. The Porto das Barcas eggshells have a dendrospherulitic morphotype with a prolatocanaliculate pore system. This morphotype was also recognised in eggshells from a clutch with associated Torvosaurus embryos at the Porto das Barcas locality. A preliminary cladistic analysis of eggshell morphology suggests theropod affinities for the Casal da Rola eggs, but is unable to resolve the phylogenetic position of the Porto das Barcas eggs. The eggshells at both sites are preserved in distal flood plain mudstones and siltstones. Carbonate concretions within the deposits indicate paleosol development.     

On the systematic position of the Early Cretaceous fern genus “Athyrium”

The oldest fossils assigned to Athyrium (mostly based on the sorus morphology) comprise fronds and spores from the Lower Cretaceous of Northeast Asia. However, most molecular dating suggests that extant Athyrium diverged from its sister genus during the Eocene or later, implying that the Cretaceous fossils probably belong to another polypodiaceous taxon. By examining the sorus morphology of extant genera related to the family Athyriaceae, we found that the primary diagnostic feature for assigning the Cretaceous fossils to Athyrium, i.e., the sorus shape, is common to the entire extant family, or plesiomorphic for the genus. As the fronds are more commonly preserved than the reproductive parts, we compared the fossil frond morphology with those of living taxa of the family that is divided into two types. The Cretaceous fossil we examined here bears the frond’s costal groove characters on adaxial side, which is more closely related to that of the Deparia-clade instead of the clade including Athyrium and other genera of the family. The observation is further confirmed by the cladistic analysis using morphological characters. The systematic position of the Early Cretaceous “Athyrium” was resolved as a stem member of the total Athyriaceae using a tip-dating approach with the Fossilized Birth-Death model in a Bayesian framework. Our study suggests that Early Cretaceous fossils previously assigned to Athyrium require taxonomic revision.     

Late Miocene—Early Pliocene paleotemperatures for California from marine diatom evidence

Paleotemperatures have been interpreted from the evidence of the diatom flora for an Upper Miocene section of marine diatomaceous sediment near Lompoc, California. The diatom flora has been compared with the distribution of modern diatoms in surface sediments of the North Pacific Ocean to propose a Miocene sea paleotemperature curve for this area of California. Temperatures declined sharply in the Late-Mohnian (Upper Miocene) to a winter minimum of about 10°C. Thereafter, a gradual and fluctuating rise in temperature characterized the latest Miocene (Delmontian); minimum seasonal temperatures approached 17°C by the Early Pliocene.This diatom assemblage paleotemperature curve is supported by other evidence. Independent studies of particular diatom temperature indicator species show the same trends, as do the paleotemperature indications of a fossil fish fauna and the foraminiferal fauna in the section. Furthermore, the curve shows a marked correspondence to paleotemperature curves based on planktonic foraminifers and on radiolarians for the Upper Miocene of southern California, providing an additional tool for paleotemperature reconstruction.     

Dinosaur footprints from the Early Jurassic of Le Mazel (Lozère,Southern France)

During the 20^th century, the first dinosaur tracks of the Causses Basin were identified at Saint-Laurent-de-Trèves, in the Parc National des Cévennes (southern France). A recent excavation reveals a new theropod tracksite in the Hettangian deposits from Le Mazel, 2 km from the historical tracksite at Saint-Laurent-de-Trèves. The tracks are here described combining a biometric approach and 3D imaging photogrammetry. The main track-bearing surface bears 64 in situ tridactyl footprints preserved as concave epireliefs. Two morphotypes were identified, a “Grallatorid” morphotype and a “Kayentapus” morphotype. Footprints belonging to the first morphotype are closely similar to Grallator lescurei, Grallator minusculus, and Grallator sauclierensis. This study shows the difficulty to distinguish quite similar tridactyl tracks from an ichnotaxonomic point of view and highlights the importance of detailed biometric comparisons. Tracks are preserved in a brown to yellowish dolomudstone showing abundant cryptalgal laminites and mud cracks. These deposits were accrued in shallow environments such as intertidal and supratidal zones of a tidal flat.     

Fauna and Predator-Prey Relationships of Ettling,an Actinopterygian Fish-Dominated Konservat-Lagerst?tte from the Late Jurassic of Southern Germany

The newly recognized Konservat-Lagerstätte of Ettling (Bavaria), field site of the Jura-Museum Eichstätt (JME), is unique among Late Jurassic plattenkalk basins (Solnhofen region) in its abundant, extremely well preserved fossil vertebrates, almost exclusively fishes. We report actinopterygians (ginglymodins, pycnodontiforms, halecomorphs, aspidorynchiforms, “pholidophoriforms,” teleosts); turtles; and non-vertebrates (echinoderms, arthropods, brachiopods, mollusks, jellyfish, sponges, biomats, plants) in a current faunal list. Ettling has yielded several new fish species (Bavarichthys incognitus; Orthogonikleithrus hoelli; Aspidorhynchus sanzenbacheri; Macrosemimimus fegerti). Upper and lower Ettling strata differ in faunal content, with the lower dominated by the small teleost Orthogonikleithrus hoelli (absent from the upper layers, where other prey fishes, Leptolepides sp. and Tharsis sp., occur instead). Pharyngeal and stomach contents of Ettling fishes provide direct evidence that Orthogonikleithrus hoelli was a primary food source during early Ettling times. Scarcity of ammonites and absence of vampyromorph coleoids at Ettling differ markedly from the situation at other nearby localities in the region (e.g., Eichstätt, Painten, Schamhaupten, the Mörnsheim beds), where they are more common. Although the exact biochronological age of Ettling remains uncertain (lack of suitable index fossils), many Ettling fishes occur in other plattenkalk basins of Germany (e.g., Kelheim) and France (Cerin) dated as Late Kimmeridgian to Early Tithonian (eigeltingense horizon), suggesting a comparable geologic age. The Ettling deposits represent an independent basin within the larger Upper Jurassic “Solnhofen Archipelago”, a shallow subtropical sea containing scattered islands, sponge-microbial and coral reefs, sandbars, and deeper basins on a vast carbonate platform along the northern margin of the Tethys Ocean.     

First multi-proxy record of Jurassic wildfires from Gondwana: Evidence from the Middle Jurassic of the Neuquén Basin,Argentina

Wildfires play a crucial role in recent and ancient ecosystem modeling but their detailed history on the Earth is still not well recorded or understood. The co-occurrence of charcoal and pyrolytic polycyclic aromatic hydrocarbons (PAHs) is used for the recognition of wildfires in geological record that may have implications for the analysis of the terrestrial environment, ecosystems, climate and the level of atmospheric oxygen. Here we present the first multi-proxy evidence of wildfires on the Gondwana continent during the Jurassic, based on the occurrence of charcoal and pyrolytic PAHs in the Middle Jurassic of the Neuquén Basin, Argentina. This is the first evidence of wildfire in the Aalenian, the lowest stage of the Middle Jurassic, and one of the few records of wildfires in the Bathonian. Temperature interpretations, derived from charcoal reflectance data, show that charcoals formed in low temperature surface fires that only sporadically reached the higher temperatures, possibly related to crown fires. The occurrence of charcoals in the Middle Jurassic deposits confirms recent results that the atmospheric oxygen level reached at least 15% during the Middle Jurassic times.