A camel skeleton in a desert environment in Abu Dhabi was monitored for 15 years to record stages of weathering, dispersal, carnivore action and trampling in this extreme environment. Weathering was substantially less rapid than that recorded in tropical environments, being slower both in inception and in later development. Skeleton dispersal was mixed, with a core group of ribs and vertebrae remaining close to the death site, but individual bones being traced for up to 60 m and many disappearing altogether. Scavenging took place, and the size of tooth marks indicated foxes and jackals. Trampling was the major source of breakage of bones, most of which were too robust for small carnivores like foxes and jackals to break.
The Lower Jurassic aeolienites of the Clarens Formation in southern Africa contain unique sedimentary structures that are unlikely to be non-biogenic. They are also unlike any known modern or ancient trace fossils. Here, some nigmatic, horizontal,regularly-oriented sedimentary structures are described, which occur in association with other trace fossils as well as features that were previously nterpreted as nests of termites or termite-like ancient social nsects. These spectacular structures are exposed in enormous profusion as straight, ~5 mm cylinders with strong compass orientation, in parallel alignment with one another and to ancient horizontal bedding planes. Their fill is identical to that of the host rock: clean, well-sorted, very fine- to finegrained quartz-arenite. In cross-section, each structure is defined by a subtle, ~0.1 mm thin, concentric gap.
Without comparable modern biogenic structures, the biological origin of the structures is uncertain. Their strong compass orientations are, however, also inconsistent
with an inorganic origin, even though they may resemble pipey concretions generated by flowing groundwater. Nonetheless, this paper, based on spatiotemporal distribution patterns of the oriented structures, their locally high abundance and association with obvious trace fossils, as well as other sedimentological and palaeontological lines of evidence, argues that the compass structures may be products of ancient social invertebrates living in a resource-limited, semi-arid to arid environment. Furthermore, the compass structures as well as the accompanying structures of the predominantly aeolian Clarens Formation collectively imply the recurrence of favourable ecological parameters (e.g., moist ubstrates) related to episodic climate fluctuations in the Early Jurassic of southern Pangaea (i.e., southern Gondwana).
At least two titanosaurian sauropod taxa have been discovered in the Early Cretaceous Dinosaur Beds of northern Malawi, Africa. One of these, Malawisaurus dixeyi, is represented by cranial elements, 18 cervical vertebrae, 10 dorsal vertebrae, a sacrum, 51 caudal vertebrae, 24 chevrons, pectoral elements, pelvic elements, and dermal armor, all of which are described and illustrated. The cranial elements indicate that Malawisaurus had a short, high macronarian skull. Karongasaurus gittelmani gen. et sp. nov. is more derived than Malawisaurus but is represented only by a dentary and isolated teeth. Some indeterminate vertebrae may also belong to Karongasaurus or another taxon, but not to Malawisaurus. The shape of the teeth and jaw, and the restriction of teeth toward the anterior part of the jaw in Karongasaurus are different from Malawisaurus and suggest that Karongasaurus had a long, low skull. Thus, the sauropods from the Malawi Dinosaur Beds demonstrate extreme morphological variation in titanosaurian jaws, teeth, and probably skull shape. Variation in tooth and skull morphology, because of its relevance to feeding, was likely of significance in resource partitioning among titanosaurian sauropods in the Early Cretaceous ecosystem.
Fossil tracks should be recorded by methods that foster detailed ichnological analysis. Although outline drawings remain the standard currency of footprint illustra- tion, their simplicity entails a tremendous loss of information. By contrast, monocular photographs are highly detailed but often suffer from suboptimal lighting, which can cause misperceptions. Anaglyph stereo imaging offers a compact, scale-independent format for illustrating and presenting the complex three-dimensional (3-D) shape of dinosaur footprints. Using examples from the Upper Triassic Fleming Fjord Formation of East Greenland, we address the benefits of anaglyphs to the exploration and exposi- tion of theropod tracks in both the field and laboratory. We find that the addition of ste- reopsis to other available depth cues (shading, cast shadows) maximizes the information content of a 2-D image while minimizing erroneous or ambiguous percep- tions of shape.
The reconstructed distribution of the major pneumatic diverticula systems in the sauropod neck might hint towards pneumatic stabilization or operation of the long neck, which was investigated considering anatomical and mechanical aspects of soft- tissue reconstructions in the neck of sauropods as well as experimental data. The mechanical role of pneumatic bodies in a generalized segmented beam of Styrodur™ blocks, which was stabilized by air-filled tube-like balloons, was tested with an experi- ment. A support effect was evident already with one ventral pneumatic system. Adding further pneumatic systems increased the load capacity of the beam. Furthermore, the presence or absence of proximal intersegmental blocks, pressure changes within the balloons, proximal fixation of the balloons or their fixation at each segment respec- tively, and the degree of segmentation of the pneumatic systems changed the effi- ciency of support. In the necks of sauropods, pneumatic support would hinge on the specific recon- struction of the pneumatic diverticula, sufficiently high pressures and a possibility for regulating pressure of the pneumatic system. Only if pneumatic diverticula would extend beyond their bony boundaries at the vertebral surface, and if one or more pres- sure regulating mechanisms were present, would a support effect be an option. Because none of these factors can be reliably reconstructed on an osteological basis, the hypothesis of pneumatic neck support in sauropods remains hypothetical. How- ever, the combination of pneumatic support with other bracing mechanisms in the sau- ropod neck results in a consistent constructional morphological model for a pneu aided neck support in sauropods.
Worldwide distribution of cephalopod limestone biofacies distribution is used herein to assess the reconstruction of the North Gondwana margin, with implications for southern hemisphere palaeobiogeography during the Silurian-Early Devonian. Three areas are of concern: the Tinduf Basin (Northwest Sahara, Morocco), the Uppony Mountains (Northeast Hungary), and perhaps the Ukrainian continental platform, which may have been part of northern Gondwana.
Two new species of the endemic genus Stertomys (Mammalia, Rodentia, Gliridae) are described from the Late Miocene fissure filling Biancone 1 on the palaeoisland Gargano (Province of Foggia, Italy): S. daamsi and S. daunius. A third new species, Dryomys apulus, presents no endemic features at the generic level and is assigned to the extant genus Dryomys. The new taxa suggest that faunal immigration to Gargano occurred in one event, and that the Biancone deposit is, at most, Late Miocene in age. Additionally, an analysis of all fossil Myomiminae argues that Stertomys belongs to that subfamily, and that it may be derived from Myomimus dehmi or Miodyromys aegercii.
Evidence is presented from fossil shells and living species of the colonial radiolarian Acrosphaera that maturer central capsules with shells can produce daughter central capsules and shells by binary fission. These data indicate that in colonial collosphaerid radiolaria, at least, proliferation of central capsules can occur after maturation and may account for rapid increase in biomass and population size in response to favourable environments. This augments prior evidence that central capsules of non-shelled colonial radiolarin can proliferate by binary fission. Also, these observations extend our understanding of the pattern of silicification and shell formation to include two possibilities: (1) the current view of "simultaneous shell deposition" where all of the skeletons are deposited at nearly the same time following multiple divisions of skeletonless central capsules and (2) "successive shell depositon," where mature central capsules with shells give rise to additional ones through delayed binary fission. These observations have interesting implications for life cycle dynamics of radiolaria in modern and paleo-oceanic environments
Several upper molars and part of a maxilla of a large rhinocerotid were collected from two localities in coastal facies of the upper unit of the Chitarwata Formation at Zinda Pir Dome in western Pakistan. Preserved features of the dentition are widely symplesiomorphic and do not permit clear assignment to a known species from the diverse rhinocerotid fauna at Dera Bugti or to the rhinocerotini subtribes. The teeth of the rhino from the upper unit of the Chitarwata Formation have a rudimentary likeness to another enigmatic but smaller species, Rhinoceros blandfordi, from Bugti Hills, suggesting a possible evolutionary link. However, additional fossils from the region are required to test this supposition. Likewise, the well-established pattern of barrier-free rhinocerotoid dispersal between the Indian subcontinent, Europe, and Asia during the early Miocene also makes it plausible that this large rhinocerotid came to the Indian subcontinent as part of an early Miocene immigration event.
The middle Pliocene warm period represents a unique time slice in which to model and understand climatic processes operating under a warm climatic regime. Palaeoclimatic model simulations, focussed on the United States of America (USA), for the middle Pliocene (ca 3 Ma) were generated using the USGS PRISM2 2º x 2º data set of boundary conditions and the UK Meteorological Office’s HadAM3 General Circulation Model (GCM). Model results suggest that conditions in the USA during the middle Pliocene can be characterised as annually warmer (by 2º to 4ºC), less seasonal, wetter (by a maximum of 4 to 8 mm/day) and with an absence of freezing winters over the central and southern Great Plains. A sensitivity experiment suggests that the main forcing mechanisms for surface temperature changes in near coastal areas are the imposed Pliocene sea surface temperatures (SST’s). In interior regions, reduced Northern Hemisphere terrestrial ice, combined with less snow cover and a reduction in the elevation of the western cordillera of North America, generate atmospheric circulation changes and positive albedo feedbacks that raise surface temperatures. A complex set of climatic feedback mechanisms cause an enhancement of the hydrological cycle magnifying the moisture bearing westerly wind belt during the winter season (Dec., Jan., Feb.). Predictions produced by the model are in broad agreement with available geological evidence. However, the GCM appears to underestimate precipitation levels in the interior and central regions of the southern USA.
Suture patterns in shelled cephalopods are periodic structures and can be described using Fourier methods when points along the pattern are described by two parametric equations. One equation describes the angular position along the circumference of the phragmacone, and another describes the height along the length of the shell. The angular position is amenable to Fourier description transformed to the difference between the observed angle and the angle expected if the suture line were straight. An accurate reconstruction of ammonitic suture patterns is accomplished with few amplitudes. Applying the method to the digitized suture patterns provides a more accurate means of interpolation than linear interpolation, necessary for comparison between suture patterns. Simple "nautilitic" and complex "ammonitic" suture patterns from the literature are used to demonstrate application of the method. Ontogenetic series of suture patterns may develop first by increasing variability in their height, and only later by increasing variability in the angular positions. The method invites new approaches of analysis, including different approaches to nearest neighbor analysis to determine patterns of similarity between suture patterns.
A trackway, probably made by a large terrestrial turtle, is reported from Hidden
Valley Quarry, Judith River Formation, Golden Valley County, south-central Montana.
These fossil tracks are compared to modern tracks of Galapagos tortoises (Geochelone
elephantopus) in captivity on substrates with variable moisture content. The fossil
tracks were made on fine-grained substrate saturated with water. Further, in conjunction
with traces of burrows likely produced by worm-like orangisms, these turtle tracks
suggest a feeding behavior analogous to modern wood turtles (Clemmys insculpta).
After detecting the underground movements of worms, wood turtles have been shown
to alter their movements in such a manner that has been referred to as a stomp. A similar
behavior may have occurred in the Cretaceous turtle track maker.
A collection of primitive titanosauriform sauropods from the Jones Ranch locality, Early Cretaceous Twin Mountains Formation (∼112 Ma), central Texas, represents one of the richest accumulations of sauropod bones in North America. Autapomorphic characters of the taxon include cranial and mid-caudal neural arches with distinct intraprezygapophyseal laminae (tprl), accessory vertebral laminae on cranial dorsal neural arches, and dorsal neural spines that lack a postspinal lamina. Non-vertebral skeletal elements referred to the genus Pleurocoelus from the Arundel Formation of Maryland and Virginia possess some diagnostic morphological-characteristics and can be compared with the Jones Ranch sauropod. The latter differs from Pleurocoelus in the shape of the caudoventral margin of the maxilla, the shape of the distal scapular blade, and the shape of the proximal condyle of the tibia. The Jones Ranch sauropod is also morphologically distinct from all other sauropods described and named from the Early Cretaceous of North America. Cladistic analysis places this sauropod within Titanosauriformes. The Texas sauropod does not possess synapomorphies of Somphospondlyli, and derived characters that have been used to define the Titanosauria are also absent, affirming its placement as a basal titanosauriform. The new taxon from Texas is known from more material than any other North American Early Cretaceous sauropod. Description of the taxon increases the diversity of sauropods in North America during the Early Cretaceous and provides-more complete, associated material that can be compared to new discoveries from this time period.
Several large tridactyl undertracks made by between four and six dinosaurs are preserved on a single bedding plane in the Anapra Sandstone (Late Albian, Creta- ceous) at Cerro de Cristo Rey, Doña Ana County, New Mexico. Because the Anapra Sandstone is herein correlated lithostratigraphically and ichnotaxonomically with the Dakota Sandstone, it is proposed that these tracks extend the southern geographic range of the Dakota Megatracksite Complex approximately 500 km. We assign the tracks described here to the ichnogenus Magnoavipes based on morphology and age (latest Albian), although several of the tracks are larger than any published data on this ichnotaxon. Also, the presence of Caririchnium along with Magnoavipes has biostrati- graphic significance and confirms the value of the ichnofacies concept.
Twenty-five species of Lauraceae cuticle are described from 120 fossil-bearing samples from two Early Miocene basins in southern New Zealand; the St Bathans Paleovalley of the Manuherikia Group, and the Gore Lignite Measures of the East Southland Group. The genera Endiandra and Cryptocarya are identified, which are no longer in the extant flora of New Zealand, and Beilschmiedia and Litsea which are in the extant flora. In the St Bathans Paleovalley it is likely that at least 22 species were growing as part of a single broader community. The presence of Lauraceae at this latitude in New Zealand and their high diversity clearly implies warmer temperatures than currently exist at lowland locations at that latitude today, which lie to the south of the existing limit of the family.
The Paleogene record of Afro-Arabia is represented by few fossil localities, most of which are coastal. Here we report sedimentological and paleontological data from continental Oligocene strata in northwestern Ethiopia. These have produced abundant plant fossils and unique assemblages of vertebrates, thus filling a gap in what is known of Paleogene interior Afro-Arabia. The study area is approximately 60 km west of Gondar, Chilga Woreda; covers about 100 km2; and represents as few as 1 Myr based on radiometric dates and paleomagnetic chronostratigraphy. The sedimentary strata are 150 m thick, and dominated by kaolinitic and smectitic mudstones and airfall tuff deposits. Five main paleosol types are interpreted as representing Protosols (gleyed or ferric), Histosols, Gleysols, Vertisols, and Argillisols. Varied, poor drainage conditions produced lateral variation in paleosols, and stratigraphic variation probably resulted from lateral changes in drainage conditions through time. Vertebrate fossils occur in sediments associated with ferric Protosols and occur with fruits, seeds, and leaf impressions. Plant fossils also occur as in situ forests on interfluves, leaf and flower compressions associated with in situ carbonized trees in overbank deposits (Gleyed Protosols), and compressions of leaves, twigs and seeds in tuffs. Plant fossil assemblages document diverse forests, from 20-35 m tall, of locally heterogeneous composition, and representing families occurring commonly (legumes) or uncommonly (palms) in forests today. Sedimentological and paleobotanical data are consistent with a nearly flat landscape where a meandering river and ample rainfall supported lush vegetation. Over time, the region was subject to intermittent ashfalls. A unique fauna of archaic mammalian endemics, such as arsinoitheres and primitive hyracoids, lived here with the earliest deinotheres.
A partial left and right manus of a gomphotheriid are described from earliest Pleistocene deposits of 111 Ranch in southeastern Arizona, USA. The discovery of these well preserved manuses provides a rare opportunity to describe these elements of a gomphotheriid in North America. I provide detailed descriptions and measurements as well as comparisons of the manuses with those of other extant and extinct proboscideans. Analyses of the manuses indicate it was a small gomphotheriid, possibly a small female, having morphological attributes more similar to other gomphotheriids, then ele-phantids and mammutids. The gomphotheriids Stegomastodon and Rhynchotherium have both been previously reported from 111 Ranch.
The comment by Smith et al. rejects a previous interpretation of Middle Ordovician fossils as holothurians. This rejection is based on the use of inappropriate techniques to study the fossils, and insufficient consideration of their taphonomy. The fossils can be shown not to be sponges (the suggested alternative interpretation), and despite the taphonomic limitations, do show echinoderm characters such as the pentagonal oral ring and ambulacral structures.
The earliest known brachyurans, or true crabs, are of Early and Middle Jurassic age. In general, they are rare and known from either a single or a few specimens only. Here we record a new genus and species of homolodromioid crab of Bajocian (early Middle Jurassic) age from Calvados (northwest France), based on a unique dorsal carapace. On the basis of carapace morphology, this is here assigned to the primitive family Prosopidae, but distinguished from other members due to the carapace grooves and tubercles and conspicuously large orbital fossae.
The mode of locomotion of the basal sauropodomorph Plateosaurus engelhardti, known from numerous finds from the late Triassic of Central Europe, has been extensively debated. Some early and recent research results indicate that the forelimb could not play role in quadrupedal locomotion. Other authors suggested facultative or even permanent quadrupedality. This would require adaptations of the range of motion and the stability of the manual digits to the high forces caused by locomotion. An analysis of the hyperextension capabilities of the hand can therefore determine if the manus is adapted for locomotion. This study examines the capabilities of the manus of P. engelhardti using digital 3D modeling. The motion ranges of the digits were simulated in a computer-aided engineering (CAE) program, and the hyperextension capability of the entire manus was tested. We find that the hand of Plateosaurus was not able to support the animal during quadrupedal locomotion, but may rather have been a specialized grasping organ. Therefore, P. engelhardti must have been an obligate biped.
Following a preliminary historical survey of the Cenozoic Clypeina marginoporella Michelin, 1845, which is the type species of the respective genus, and of the Mesozoic Clypeina sulcata (Alth, 1882), the point was made that these two species may not be ascribed to the same genus. Accordingly, the new genus Aloisalthella is introduced with Clypeina sulcata as type-species. In addition, the generic diagnosis of Clypeina is amended (i.e., shortened) in order to exclude all features that are not present in its type, e.g., there are no verticils of sterile laterals inserted between successive verticils of fertile laterals. A rather large collection of algae was used to illustrate some key characteristics of these algal taxa as well as a few features rarely observed in C. sulcata.
Based on a well-preserved specimen from Eocene Baltic amber (Kaliningrad region, Russia), Trichodesma fennosarmatica sp. nov. is described and illustrated. It is the fourth fossil species of this genus. The new species is similar to the extinct Trichodesma
electra Zahradník and Háva, 2017, T. groehni Zahradník and Háva, 2017, and T. amberica Zahradník and Háva, 2017 from Baltic amber, but differs in the number of elytral tufts of erect setae that are present. A key to fossil species of Trichodesma is
The earliest known rugosan-bryozoan intergrowth is reported from the early Katian of Estonia. A specimen of Orbignyella germana Bassler, 1911, from pelmatozoan-bryozoan-receptaculitid reefs of the Vasalemma Formation shows intergrowth with rugosans Lambelasma carinatum Weyer, 1993. The morphology of the bryozoan colony does not show any malformations or changes in zooid size near the embedded rugosans. It is likely that intergrowth between L. carinatum and O. germana was purely accidental. Relatively high population densities and restricted space for growth in the reef may have caused this intergrowth. Rugosans may have benefitted from this association
in achieving a stable substrate in shallow and hydrodynamically active waters of the reef environment, whereas bryozoans obviously used corals as a substrate. Lambelasma may have been especially prone for intergrowth with bryozoans as it participates in three associations in the Late Ordovician of Estonia.
Stegosaurs were not built for rapid locomotion. Instead of fleeing from predators, they probably used their spiked tails as 'thagomizers' for defense. Kinetic/dynamic modeling in a computer-aided engineering program allows either using prescribed joint motions to determine joint forces or torque input models that deliver accelerations and moment of inertia of the tail tip spikes. Prescribed motion models based on a CAD range of motion analysis of Kentrosaurus and motions observed in extant long-tailed reptiles give results consistent with those of models using torque values calculated from detailed CAD reconstruction of muscle cross sections and moment arms. Both indicate that the tail of Kentrosaurus was a dangerous weapon, capable of inflicting painful slashing injuries and debilitating penetrating trauma, even on large theropods, across a large portion of its motion range. Continuous rapid motion was at least sufficient for the spikes to slash open the integument or penetrate soft tissues and fracture ribs or facial bones, while aimed whiplash blows may have had sufficient energy to fracture sturdy longbones.
A partial ichthyosaur skeleton is described from the Grayson Marl (Late Cretaceous: Early Cenomanian, ~97 Ma) from Tarrant County, Texas. Prior to this discovery, the Cretaceous record of Texas ichthyosaurs consisted of isolated vertebrae. The new specimen consists of a partial disarticulated skull and postcranial elements including a postfrontal, parietal, quadrate, angular, surangular, several teeth, and several vertebrae including the atlas-axis complex, coracoid, and articulated partial forelimb. The forelimb is diagnostic in having a zeugopodial element anterior to the radius, rectangular phalanges, and an intermedium that does not make contact with the humerus allowing referral to Platypterygius von Huene 1922. This occurrence is the youngest of that taxon in Texas and is consistent with late European occurrences of the genus Platypterygius.
The enigmatic cyamodontoid placodont Cyamodus hildegardis from the Besano Formation (Middle Triassic) of the Alpine area of Switzerland and northern Italy has previously been reconstructed with a broad, laterally expanded main armour (carapace) and a separate smaller pelvic shield, lending this species a fairly sprawling appearance. A re-examination and a literature review of the postcranial dermal armour and endoskeletal elements of the three best preserved articulated specimens of the species leads to new interpretations of the dermal armour and associated underlying postcranial bones, as well as a new life reconstruction. The carapace of C. hildegardis, carrying a series of similar-sized, enlarged lateral armour plates, is rounder and less laterally expanded than previously hypothesised. The separate pelvic shield, also carrying a smaller set of lateral armour plates that decrease in size with an anteroposterior gradient, covers mainly the pelvic girdle and the base of the tail. The rather short tail is armoured by four series of armour plates that show a simple anteroposterior gradient of size reduction in keeping with an equivalent size reduction in the caudal vertebrae. Until further fossils are recovered, the internal organisation of dermal plates within the two armour shields of C. hildegardis remains little known.
New data from a detailed study of the type and topotype collections of the type species of Heritschioides confirm the unique status of the genus as colonial and bearing extra septal lamellae. The associated microfossils establish its age as late Serpukhovian to early Bashkirian. The close connection of the cardinal septum to the median lamella and the axial structure points to the family Aulophyllidae. However, the inconsistent role of the protosepta in the formation of the median lamella is unique for Heritschioides. This feature and the colonial growth form allow its assignment to a separate subfamily, the Heritschioidinae Sando, 1985, which is closely related to the subfamily Aulophyllinae. So far, the subfamily Heritschioidinae is known to occur only in rocks along the western margin of North America.
This study is a thorough assessment on the morphology and taxonomy ofMourasuchus amazonensis, a fossil crocodylian of the Caimaninae clade from the lateMiocene Solimões Formation of Brazil. A thorough redescription of the holotype of thespecies (DGM 562-R, a nearly complete skull with an associated incomplete left man-dible) is performed together with the redescription of the specimen UFAC-1424, a pos-terior portion of the skull with associated mandibular remains, and the description ofthe specimen LACM-160157, also a posterior portion of the cranium. As such, thispaper brings the most comprehensive osteological study of M. amazonensis to be per-formed to date, enabling a thorough taxonomic reassessment of the species in ques-tion. This reassessment confirmed M. amazonensis as a valid species, with twoautapomorphies and two other distinctive characters. UFAC-1424 and LACM-160157are assigned as Mourasuchus cf. M. amazonensis, pending further studies on the tax-onomy of the species in order to clarify whether these specimens belong to the same species as DGM 526-R. Additionally, implications of the morphology observed in M. amazonensis for the taxonomic status of other Mourasuchus species are also dis-cussed, especially with respect to M. nativus, which is currently a junior synonym of M. arendsi.
In this study, two new species of anthracine bee flies are described and one previously described species is reassessed. Anthrax succini Greenwalt and Evenhuis sp. nov. is the first of the very speciose genus Anthrax and only the second bombyliid to be described from Dominican amber. The previously described Anthrax dentoni Lewis, 1969 was re-examined and reassigned to Anthracinae incertae sedis due to lack of morphological detail required for generic assignment. Eoanomala melas Greenwalt and Evenhuis gen. and sp. nov. is described from the Middle Eocene oil shales of the Kishenehn Formation. Eoanomala melas contains a number of character states that are not found together in any extant genera and, although it may fit within the tribe Villini, it does not appear to be closely related to the extant constituents of that clade.
Tenontosaurus tilletti Ostrom, 1970, historically assigned to ‘basal Iguanodontia,’ is a species of bipedal herbivore from the Lower Cretaceous (Aptian-Albian). Previous publications on the anatomy of the species have consisted of a cursory account of specimens collected in the Cloverly Formation of the Bighorn Basin of Montana, as well as a more detailed description of the postcranial skeleton by Forster (1990). To date, the skull of T. tilletti remains poorly described due to lack of research and poorly preserved specimens. The present study is an attempt to rectify the situation with material referable to Tenontosaurus tilletti, collected from southeastern Oklahoma. In particular, an especially well-preserved skull (OMNH 58340) of T. tilletti was CT-scanned and virtually separated into its component elements. These elements, as well as reconstructions of the internal spaces for soft tissues, such as the endocast and cranial nerve foramina, are herein described and illustrated in detail. This description is used to conduct a novel systematic analysis. The analysis strongly supports the genus Tenontosaurus, as well as its position relative to ‘hypsilophodonts’ and iguanodontians, and largely agrees with previous analyses.
Common, recurrent and pervasive homeomorphism makes precise biostratigraphy crucial for correct interpretations of Lower Kimmeridgian ataxioceratin ammonites (e.g., Ataxioceras Fontannes, 1878 and Ataxioceras [Schneidia] Atrops, 1982) on the basis of analyzing complete specimens. Ataxioceras is not conclusively known even in epicontinental, Submediterranean areas since the majority of nominal species were erected during pioneer times for ammonite systematics and biostratigraphy, and updated information is really limited. Reports of Ataxioceras from Mexico reveal that the material is not conclusive for accepting these records as real occurrences, which is corroborated by hundreds of specimens retrieved from outcrops sampled bed-by-bed during the last two decades. The potential occurrence of Ataxioceras in Mexico is approached through the analysis of the single, complete, in-volume preserved specimen illustrated as Ataxioceras (Ataxioceras) lopeztichae sp. nov. by Cantú-Chapa, 1991, and the revision its systematic and palaeobiogeographic meaning is made. The precise analysis of shell morphology, ribbing and peristomal structure has been supported with complementary comparisons with involute morpho-species of Ataxioceras and Schneidia. Reinterpretation of the Mexican type as Schneidia lopeztichai (Cantú-Chapa) of a latest Platynota to earliest Hypselocyclum age is promoted, and favoured its occurrence in relation with colonization events under Hispanic Corridor influence. A potential western colonization by Early Kimmeridgian ataxioceratins via the Panthalassa Ocean is not supported by reported records of assumed Ataxioceras from north-easternmost Gondwana and terrane complexes of the easternmost Asian Block since they refers to unidentified homeomorphs.
German paleontology has a long tradition and is still very active and innovative in many fields. Fields with the highest impacts are Neogene to Recent micropaleontology with paleoceanographic and climate focus as well as geobiology and paleoecology. Systematic paleontology is well represented in Germany and leading taxonomic expertise is present for many groups although the impact of this research is necessarily low. Conservation of this expertise is important but visibility should be enhanced by cooperation with researchers from other disciplines. Analytical paleobiology is too weak in Germany with a few exceptions, as is the deep-time perspective of evo-devo research and efforts should be made not to fall further behind here. The greatest risk for German paleontology is the continued closure of university departments and the replacement of retired paleontologists by non-paleontologists. This threatens the future of our students in science and the paleontological research community may fall below a critical mass which is needed for innovative research. Some of these problems fall in the responsibility of the paleontologists themselves (e. g., lack of innovative approaches, apparent absence of practical/economic applicability, tactical mistakes) but others are the result of administrative actions to save or shift resources independent of the quality of research and teaching.
The Ocean Drilling Program (ODP) has amassed large databases (including paleontological) as a result of its research on the geology of the ocean floor. ODP has begun to present its research results in electronic proceedings that will soon completely displace paper publications. Palaeontologia Electronica (PE) has pioneered the concept of an all-electronic paleontological journal with no paper equivalent. The publication and distribution of electronic data and scholarly papers are no longer the cutting edge of publishing technology; the cutting edge now moves to the next generation of electronic documents. The wide experience gathered by ODP and PE, from the collection of drilled cores and data, through preliminary reports to final scholarly publication, has provided the historical background. The next generation of electronic publications will include refinement of some of the present elements supported by technological improvements to create a product that meets the full spectrum of needs within the scientific community. The goals for these publications should include the creation of a truly dynamic platform for the exchange of information and ideas; the permanent, long-term archive of published materials and the data on which they are based; improved world-wide access; and a realistic and improved presentation of text, data, graphics, and other media.
This study describes a total of 95 calcareous benthic foraminiferal taxa from the Pliocene-Pleistocene recovered from IODP Hole U1341B in the southern Bering Sea with illustrations produced with an optical microscope and SEM. The benthic foraminiferal assemblages are mostly dominated by calcareous taxa, and poorly diversified agglutinated forms are rare or often absent, comprising only minor components. Elongate, tapered, and/or flattened planispiral infaunal morphotypes are common or dominate the assemblages reflecting the persistent high-productivity and hypoxic conditions in the deep Bering Sea. Most of the species found in the cores are long-ranging, but we observe the extinction of several cylindrical forms that disappeared during the mid-Pleistocene Climatic Transition.