Fossil Microvertebrates

Background
Eolambia caroljonesa is the most abundant dinosaur in the lower Cenomanian Mussentuchit
Member of the Cedar Mountain Formation of Utah, and one of the most completely known
non-hadrosaurid iguanodontians from North America. In addition to the large holotype and
paratype partial skulls, copious remains of skeletally immature individuals, including three
bonebeds, have been referred to E. caroljonesa. Nevertheless, aspects of the postcranial
anatomy of this taxon, particularly the pelvic girdle, have remained ambiguous due to the
lack of associated postcranial material of larger, more mature individuals.
Methodology/Principal findings
Here we describe a recently discovered associated partial postcranial skeleton of a large
Eolambia caroljonesa. This specimen, FMNH PR 3847, provides new anatomical data
regarding the vertebral column and pelvic girdle, supplementing previous diagnoses and
descriptions of E. caroljonesa. A new phylogenetic analysis incorporating information from
FMNH PR 3847 places E. caroljonesa as a basal hadrosauromorph closely related to Protohadros
byrdi from the Cenomanian Woodbine Formation of Texas. Histological analysis of
FMNH PR 3847 reveals that it represents a subadult individual eight to nine years of age.
Taphonomic analysis indicates that FMNH PR 3847 was preserved in a crevasse splay
deposit, along with an unusual abundance of small crocodylomorph material.

Vertebrate microfossil assemblages contain abundant fossil material of small and large bodied animals recruited from the local paleocommunity that can provide important information for reconstructing regional paleoecology. The Foremost Formation is the oldest unit of the Belly River Group, and records the transition from the fully marine shales of the Pakowki Formation to the non-marine strata of the relatively well-sampled Oldman and Dinosaur Park formations. Although the Foremost Formation has relatively limited exposure and vertebrate fossil material is not abundant, it does contain some important early records of major vertebrate clades from Laramidia (e.g. ceratopsids, pachycephalosaurids). Here we document a new microfossil locality from the upper part of the formation that shows a transitional assemblage containing an abundance of terrestrial forms such as dinosaurs and other sauropsids, while still showing considerable marine influence. The proportion of marine taxa at this site is reduced relative to most sites known from the Foremost Formation, though much higher than more terrestrial sites of the overlying Oldman Formation. In addition to filling a gap in our understanding of this paleoenvironmental transition, this new site preserves two particularly significant specimens: a large, complete, cephalic spine of the hybodont shark Hybodus, and jaw fragments from the ratfish Elasmodus. This represents the first known complete cephalic spine of a hybodont shark from the Cretaceous of Alberta. The ratfish jaw fragments represent the first published record of this group from the Foremost Formation, further increasing our knowledge of chondrichthyan diversity in the Western Interior Seaway. Comparisons of this site to other microsites from the Campanian of Alberta demonstrate the utility of certain key groups, such as lissamphibians and chondrichthyans, in determining paleoenvironments from Mesozoic and Cenozoic vertebrate microsite assemblage data.

Despite a century of paleontological work in Neogene sequences of northwestern Argentina there is still much to learn about the biotic diversity in this area during Pliocene times. We report a rich microvertebrate assemblage recovered from Late Pliocene deposits of Uquía Formation, Jujuy Province, northernmost Argentina. Taxa represented in the studied sample include members of Bufonidae (Amphibia: Anura), Iguanoidea (Reptilia: Squamata), Passeriformes (Aves), Argyrolagidae, Didelphidae, Caviidae, Ctenomyidae, Octodontidae, and Cricetidae (Mammalia). Taphonomic attributes indicate that the bone concentration was produced by owls. The remains were disposed highly concentrated suggesting that the assemblage would have been generated in a short lapse, indicating a low time-averaging, retaining the main ecological signals of the past living community. The studied assemblage is noteworthy because it encompasses at least five new genera of cricetid rodents, illustrating the oldest record in northwestern Argentina for this diverse family of mammals. In spite of clear taxonomic differences at specific and generic levels, the structure of the assemblage is ecologically comparable to modern small mammal communities in terms of body mass distribution, trophic structure and abundance, with a dominance of cricetids over marsupials and caviomorph rodents. Striking differences in taxonomic composition between the Uquian assemblage and the coeval record from central Argentina indicate biogeographical distinctions since the Late Pliocene. The new Uquian cricetids show that the early divergence times for phyllotine genera proposed by several authors cannot be supported. The dominance of phyllotines in the assemblage as well as the record of Microcavia and an octodontid allow inferring arid or semiarid paleoenvironment conditions, in a more or less open habitat. The studied assemblage reflects a noteworthy faunal turnover, which implies the establishment of cricetid rodents as the dominant group in the small mammal communities. This faunal change can be associated to increasing aridity during Late Pliocene worldwide.

The Moncure microvertebrate locality in the Cumnock Formation, Sanford sub-basin, North Carolina, dramatically increases the known Late Triassic age vertebrate assemblage from the Deep River Basin. The ,50,000 recovered microvertebrate fossils include osteichthyans, amphibians, and numerous lepidosauromorph, archosauriform, and synapsid amniotes. Actinopterygian fossils consist of thousands of scales, teeth, skull, and lower jaw fragments, principally of redfieldiids and semionotids. Non-tetrapod sarcopterygians include the dipnoan Arganodus sp., the first record of lungfish in the Newark Supergroup. Temnospondyls are comparatively rare but the preserved centra, teeth, and skull fragments probably represent small (juvenile) metoposaurids. Two fragmentary teeth are assigned to the unusual reptile Colognathus obscurus (Case). Poorly preserved but intriguing records include
acrodont and pleurodont jaw fragments tentatively assigned to lepidosaurs. Among the archosauriform teeth is a taxon distinct from R. callenderi that we assign to Revueltosaurus olseni new combination, a morphotype best assigned to cf. Galtonia, the first Newark Supergroup record of Crosbysaurus sp., and several other archosauriform tooth morphotypes, as well as grooved teeth assigned to the recently named species Uatchitodon schneideri. Synapsids represented by molariform teeth include both ‘‘traversodontids’’ assigned to aff. Boreogomphodon and the ‘‘dromatheriid’’ Microconodon. These records are biogeographically important, with many new records for the Cumnock Formation and/or the Newark Supergroup. In particular, Colognathus, Crosbysaurus, and Uatchitodon are known from basins of Adamanian age in the southwestern U.S.A. These new records include microvertebrate
taxa more typical of non-Newark basins (abundant archosauriforms, temnospondyls, lungfish) as well as more
typical Newark osteichthyans and synapsid-rich faunal elements.

La grotte du Lazaret a livré de nombreuses industries acheuléennes, plusieurs restes d’anténéanderthaliens et de très nombreux restes de vertébrés (amphibiens, reptiles, oiseaux et mammifères) reflétant une importante richesse spécifique. Les différentes associations fauniques, ainsi que le degré d’évolution de certaines espèces, permettent d’attribuer les dépôts archéologiques au Pléistocène moyen final (MIS 6), en accord avec les datations radiométriques. L’étude interdisciplinaire des ensembles stratigraphiques CIII et CII supérieur a permis de reconstituer le cadre paléoclimatique et paléoenvironnemental, et de mettre en évidence une certaine variété de paysages continentaux liés à un climat relativement froid, toutefois tempéré par la position méridionale du site. La présence d’espèces de climat froid actuellement disparues du biome méditerranéen implique l’existence de conditions plus fraîches et plus humides qu’aujourd’hui. Des fluctuations sont cependant perceptibles tout au long de la séquence au travers des variations de faunes, au niveau spécifique et quantitatif, montrant une relative intensification du froid et une ouverture progressive du milieu entre les ensembles CII sup. et CIII. Le spectre faunique de la grotte du Lazaret fournit un reflet assez juste de la paléobiodiversité dans le Sud-Est de la France à la fin du Pléistocène moyen (MIS6).

This paper presents a multiproxy palaeoenvironmental study from Abric del Pastor (Alcoy, Spain), a rock shelter which has yielded evidence for Middle Palaeolithic human occupation. The sedimentary sequence has been analysed for lipid biomarker n-alkane abundances (ACL, CPI), compound specific leaf wax d 2 H and d 13 C, and bulk organic geochemistry (TOC, %N, %S), providing a record of past climate and local vegetation dynamics. Site formation processes have been reconstructed through the application of soil micromorphology. Analyses of anthracological, microvertebrate and macrofaunal assemblages from selected subunits are also presented here. Our data indicates that a variable climate marked by predominantly cold conditions persisted through most of the sequence and that Neanderthal occupations in stratigraphic unit IVd, assigned to MIS 4 or late MIS 5, occurred in a landscape setting characterised by a mosaic of biotopes. The presence of key resources inside the ravine where the site is located suggests that the occupation of the rock shelter may have been strategically motivated by a subsistence and mobility strategy which focused on zones of localised ecological resilience, such as intra-mountainous valleys or ravines, during periods of global or regional environmental downturn.

Se presentan los resultados del análisis de restos óseos y dentarios de micromamíferos (≤1 kg) recuperados en Vaquería Gruta 2 (VQG2), un sitio arqueológico localizado en el piedemonte alto de la precordillera de Mendoza (Argentina) con dataciones correspondientes al Holoceno tardío. Estos resultados se comparan con aquellos reportados para conjuntos óseos de micro-mamíferos cordilleranos del Centro-Occidente Argentino. Se realizó un análisis tafonómico para aproximarse a los posibles agentes acumuladores del conjunto óseo, sobre la base de abundancias relativas, patrones de fractura y digestión. Se anali-zaron variables orientadas a evaluar la actividad antrópica, tales como huellas de corte y termoalteraciones. Los resultados también se compararon con valores reportados en estudios tafonómicos actualísticos regionales para distintos depredadores. El análisis tafonómico permitió determinar que fueron aves rapaces los agentes responsables de la acumulación ósea recu-perada en VQG2. Esta misma fue producto, probablemente, de una acumulación mixta. Asimismo, se realizó un análisis de la composición taxonómica de VQG2. Tanto la presencia de especies extirpadas en el registro arqueológico (Reithrodon auritus) como la mayor diversidad y equitatividad en dicho registro, en comparación con los ensambles actuales de micromamíferos, permiten pensar en un escenario de mayor heterogeneidad ambiental durante el Holoceno tardío, con mayor disponibilidad de parches de recursos que en el presente. Palabras clave: zooarqueología, microvertebrados, tafonomía, heterogeneidad ambiental, Desierto de Monte, aleros rocosos, Cordillera de los Andes, Mendoza We present the results of the taphonomic and taxonomic analysis of small mammal (≤1 kg) bone and tooth remains recovered in Vaquería Gruta 2 (VQG2), an archaeological site located in the high piedmont of the Andean precordillera of Mendoza (Argentina). We compare these results with previously reported archaeological collections of small mammal bone and teeth from the Andean areas of Central Western Argentina. VQG2 is located in the Monte Desert, and according to radiocar-bon dates, was occupied within the late Holocene. With the aim of assessing possible accumulating agents of the bone ensemble , we conduct a taphonomic analysis based on the relative abundance of skeletal elements, fracture patterns, and evidence of digestion. This analysis also included variables to detect human activity, such as cut marks and thermal alterations. These results were compared with regional taphonomic studies of several contemporary predators. The taphonomic analysis indicated that avian raptors were the primary accumulating agents of the zooarchaeological record, although the collection likely resulted from multiple predators. We also evaluated the taxonomic composition of the assemblage. Both the presence of extir-pated species (Reithrodon auritus) in the archaeological record and the higher diversity and evenness of the sample in comparison to populations of modern small mammals in the study area indicate that the late Holocene exhibited a greater environmental heterogeneity and availability of patch resources than present times.

This paper presents a multiproxy palaeoenvironmental study from Abric del Pastor (Alcoy, Spain), a rock shelter which has yielded evidence for Middle Palaeolithic human occupation. The sedimentary sequence has been analysed for lipid biomarker n-alkane abundances (ACL, CPI), compound specific leaf wax d 2 H and d 13 C, and bulk organic geochemistry (TOC, %N, %S), providing a record of past climate and local vegetation dynamics. Site formation processes have been reconstructed through the application of soil micromorphology. Analyses of anthracological, microvertebrate and macrofaunal assemblages from selected subunits are also presented here. Our data indicates that a variable climate marked by predominantly cold conditions persisted through most of the sequence and that Neanderthal occupations in stratigraphic unit IVd, assigned to MIS 4 or late MIS 5, occurred in a landscape setting characterised by a mosaic of biotopes. The presence of key resources inside the ravine where the site is located suggests that the occupation of the rock shelter may have been strategically motivated by a subsistence and mobility strategy which focused on zones of localised ecological resilience, such as intra-mountainous valleys or ravines, during periods of global or regional environmental downturn.

We document here a new taxon of sphenodontian, Whitakersaurus bermani gen. et sp. nov., that is also the most complete sphenodontian fossil from the Upper Triassic Chinle Group in the south-western USA and the first Chinle sphenodontian represented by more than a single fragmentary dentulous element. The holotype was recovered during preparation of block C-8-82 from the famous Coelophysis (Whitaker) quarry at Ghost Ranch, New Mexico, and is the most complete small vertebrate recovered from the quarry. Detailed lithostratigraphy and geologic mapping demonstrate that the Whitaker quarry is in the Rock Point Formation of the Chinle Group, so Whitakersaurus is the first sphenodontian reported from this unit. Records of the phytosaur Redondasaurus at the quarry and elsewhere in the Chinle Group demonstrate that the quarry, and thus Whitakersaurus, is of Apachean (late Norian-Rhaetian) age. The sphenodontian specimen consists of incomplete left and right dentaries, a partial left? maxilla?, and impressions of a probable palatal element, all of which preserve multiple teeth. Whitakersaurus is distinct from other sphenodontians in possessing a unique combination of the following features: marginal dentition pleurodont anteriorly and posteriorly acrodont; pronounced heterodonty in dentary, with as many as 15 smaller, peglike teeth anteriorly and several larger, posterior teeth that are conical and striated; faint radial ornamentation of posterior tooth crowns; presence of c. 19 dentary teeth; and absence of a distinct flange on posterior teeth. Numerous other details distinguish it from both more primitive and more derived taxa. Whitakersaurus, therefore, helps to document further mosaic evolution and an extensive diversification event of sphenodontians during Triassic time. Although sphenodontian taxa are relatively easily recognized, widely distributed, and common small-or microvertebrate fossils, the long stratigraphic ranges of taxa known from multiple specimens hinders their utility as index fossils with which to correlate strata across Pangaea.

Se denuncia a Ulyses Pardiñas como perpetrador de varios tipos de fraudes científicos realizados en su tesis doctoral y en varios artículos respecto de la fauna, estratigrafía y cronología de Cueva Tixi. En este artículo se describen las pruebas de esos fraudes.