The structure of cranidial shape variation in the early ptychoparioid trilobites Crassifimbra walcotti, Crassifimbra? metalaspis (new combination), and Eokochaspis nodosa is explored using landmark-based geometric morphometric techniques, and is found to be generally similar among the species. Allometry is the strongest single source of cranidial shape variation within each species. The species share several trends in their respective patterns of ontogenetic shape change, but differ in the relative magnitude of these shared trends. Species-specific trends are also present. Each species follows a unique trajectory of ontogenetic shape change. The species exhibit subtle but significant differences in mean cranidial shape even at small size (sagittal length 1.75 mm); the magnitude of interspecific differences becomes larger at larger size (sagittal length 4.2 mm).

For conspecific cranidia of a given size, the major pattern of covariance among anatomical parts is essentially identical to the pattern of covariance among those parts during ontogeny. Developmentally determined covariance patterns among cranidial regions might be responsible for ontogenetic shape change and a portion of non-allometric shape intraspecific variation. Interspecific differences in cranidial shape resulted from complex local modifications to growth pattern and cannot be attributed to simple ontogenetic scaling.

The new collections permit the first description of non-cranidial sclerites of C. walcotti. A cephalic median organ is documented on C. walcotti, representing the oldest known occurrence of this structure in trilobites.

Representatives of the family Gastrodoridae were exclusively known from Jurassic deposits in central Europe. Here, the first Cretaceous species, Gastrodorus cretahispanicus n. sp., is recorded from reefal strata of the Eguino Formation (Albeniz Unit) of Albian-Cenomanian age, in western Navarra (northern Spain). Not only does the occurrence of the new species extend the stratigraphic range of the family upward for approximately 45 million years into the mid-Cretaceous, it also constitutes the first record of gastrodorids from southern Europe. For over a century, the taxonomic position of the genus Gastrodorus has been debated. It is revised here and the family Gastrodoridae is given a full superfamily status within the Anomura. The genus Eogastrodorus is also redefined. Gastrodorids underwent a remarkable size reduction from the Middle to Upper Jurassic, which may be explained by their migration into reef environments.

Morphologic analyses of a large collection of coleoid cephalopods from the Lebanese Upper Cretaceous yielded a much higher diversity than previously assumed and revealed numerous extraordinarily well-preserved, soft-part characters. An analysis of the Prototeuthidina, a gladius-bearing group with a slender torpedo-shaped body, revealed two species: Dorateuthis syriaca and Boreopeltis smithi n. sp. Previously unknown soft-part characters, such as the digestive tract, the gills, and the cephalic cartilage considerably improved our knowledge of D. syriaca. Since none of the investigated specimens show more than eight arms, similarities with modern squids are regarded as superficial. Boreopeltis smithi n. sp. is erected on the basis of its comparatively wide Paraplesioteuthis-like gladius. The latter species represents the first unambiguous record of this genus in Upper Cretaceous deposits. Phylogenetic analyses indicate that the prototeuthidid clade consists of two lineages. The plesioteuthidid lineage originates from early Jurassic Paraplesioteuthis and leads to Plesioteuthis and Dorateuthis. The other lineage is morphologically more conservative and leads to Boreopeltis.

The Middle Cambrian eocrinoid genera Lyracystis Sprinkle and Collins, 2006, from western Laurentia and Balangicystis Parsley and Zhao, 2006, from South China, described in the same year, have turned out to be closely related genera assigned to the Family Lyracystidae. Both have erect, lyre-shaped, arm-like, brachiole-bearing, feeding appendages, here termed exothecal ambulacra, that are not homologous to crinoid arms. They also have a long, multiplated stalk to elevate the theca and feeding appendages well above the sea floor, making them among the highest tiered echinoderm suspension feeders known from the Middle Cambrian. The long stalk was either inserted a short distance into the muddy sediment, or attached to rare skeletal fragments lying on the sea floor. Both genera seem well adapted to quiet-water or slow-current conditions in deeper water (150–200 m) on the outer shelf or upper slope of their respective continents.

Ediacaran trace fossils are becoming an increasingly less common component of the total Precambrian fossil record as structures previously interpreted as trace fossils are reinterpreted as body fossils by utilizing qualitative criteria. Two morphotypes, Form E and Form F of Glaessner (1969), interpreted as trace fossils from the Ediacara Member of the Rawnsley Quartzite in South Australia are shown here to be body fossils of a single, previously unidentified tubular constructional morphology formally described herein as Somatohelix sinuosus n. gen. n. sp. S. sinuosus is 2–7 mm wide and 3–14 cm long and is preserved as sinusoidal casts and molds on the base of beds. Well-preserved examples of this fossil preserve distinct body fossil traits such as folding, current alignment, and potential attachment to holdfasts. Nearly 200 specimens of this fossil have been documented from reconstructed bedding surfaces within the Ediacara Member. When viewed in isolated hand sample, many of these specimens resemble ichnofossils. However, the ability to view large quantities of reassembled and successive bedding surfaces within specific outcrops of the Ediacara Member provides a new perspective, revealing that isolated specimens of rectilinear grooves on bed bases are not trace fossils but are poorly preserved specimens of S. sinuosus. Variation in the quality and style of preservation of S. sinuosus on a single surface and the few distinct characteristics preserved within this relatively indistinct fossil also provides the necessary data required to define a taphonomic gradient for this fossil. Armed with this information, structures which have been problematic in the past can now be confidently identified as S. sinuosus based on morphological criteria. This suggests that the original organism that produced this fossil was a widespread and abundant component of the Ediacaran ecosystem.

The Tenebrionoidea is among the most diverse group of beetles, but its fossil record is rare. A definitive oldest tenebrionoid beetle, Wuhua jurassica new genus new species, is described from the Middle Jurassic of Daohugou, China. It is tentatively placed as Family incertae sedis, and distinguished from others of Tenebrionoidea by the unusual combination of following characters: body convex; head strongly deflexed, not received into prothorax; antennae filiform; pygidium absent; tarsi simple and tarsal claws pectinate. This discovery extends the time of origin of Tenebrionoidea to the Middle Jurassic. Furthermore, the record of Mesozoic tenebrionoid beetles are summarized and discussed.

Two protocetid whale vertebrae, here referred to “Eocetus” wardii, have been recovered from the riverbed of the Pamunkey River in east-central Virginia. Neither bone was found in situ, but both were found with lumps of lithified matrix cemented to their surfaces. Most of this matrix was removed and processed for microfossils. Specimens of dinoflagellates were successfully recovered and this flora clearly demonstrates that both vertebrae came from the middle Eocene Piney Point Formation, which crops out above and below river level in the area where the bones were discovered. These vertebrae are the oldest whale remains reported from Virginia and are as old as any cetacean remains known from the western hemisphere.

The Eosaukia fauna is proposed for the upper Furongian trilobite assemblage from the interval spanning from the upper part of the Hwajeol Formation to the lowermost part of the Dongjeom Formation in the Taebaek Group, Taebaeksan Basin, Korea. It is characterized by the dominance of dikelocephalid trilobites comprising Eosaukia micropora, E. bella, E. acuta, Mictosaukia cf. M. globosa, and Taebaeksaukia spinata n. gen. n. sp. Taxonomic reappraisal of the genus Mictosaukia that has been employed as an upper Cambrian index taxon in eastern Gondwana reveals that more than half of the species of Mictosaukia belong in Eosaukia. This study clarifies the generic concept of Eosaukia, which provides a more reliable biostratigraphic correlation for the upper Furongian strata in eastern Gondwanan regions. The Eosaukia fauna is correlated with the “Mictosaukia” faunas from the upper Fengshanian of North China, upper Taoyuanian of South China, and upper Payntonian of Australia.

The pelvic shield of ankylosaurian dinosaurs refers to an area of osteoderms lacking differentiated transverse bands over the pelvic region and it is used as a diagnostic character for various ankylosaur groups. The pelvic shield character varies across ankylosaur taxa but is typically coded as a binary character or is excluded from phylogenetic analyses, which obscures evolutionary trends and relationships. This study investigates for the first time pelvic shield morphology in a stratigraphic and geographic context. This paper comprehensively reviews pelvic shield morphology with firsthand observations of specimens, and proposes three categories of pelvic shield morphology. Category 1 pelvic shields have un-fused but tightly interlocking osteoderms. Category 2 pelvic shields have fused osteoderms forming rosettes and are restricted to the Late Jurassic to mid Cretaceous of North America and Europe. Category 3 pelvic shields have fused polygonal osteoderms of similar size, and are found in the mid- to Late Cretaceous of North America. Although the pelvic shield is used to characterize the Polacanthidae, an interpretation supported by this review, the validity of such a clade is dependent upon a global parsimony analysis incorporating this character. Future analyses of the Ankylosauria should incorporate a more detailed treatment of the pelvic shield to determine its diagnostic value within the group.

Longzhua loculata n. gen. n. sp., a new Pennsylvanian Archaeorthoptera (i.e., stem-Orthoptera), is described from the Tupo Formation based on 64 specimens, including an individual with parts of body and legs preserved. The range of intra-specific variation in forewing venation pattern is documented in detail. Well-preserved isolated hind wings are associated with forewings based on more complete material. The combination of character states exhibited by the new species indicates relationships with the extinct order Cnemidolestodea. Mandibular and prothoracic morphology suggest that Longzhua loculata n. gen. n. sp. had carnivorous and predatory habits.

Galecyon is one of the first appearing hyaenodontid creodonts, as well as one of the most poorly known. New specimens greatly improve our understanding of the morphology of this early Eocene genus, thereby enhance knowledge of the earliest radiation of Hyaenodontidae, and include the first associated upper dental remains, as well as fragmentary cranial remains. The new records substantially expand the stratigraphic range of the genus and allow recognition of two new species. The first, Galecyon peregrinus n. sp., is a small, early species that includes the first records of Galecyon from the earliest Eocene Wa-0 interval. The second, Galecyon chronius n. sp., is a large, terminal species, represented by numerous specimens that extend the range of the genus into the late Wasatchian. The type species, G. mordax, is restricted to specimens that are intermediate in size and stratigraphic position. Phylogenetic analysis of early hyaenodontids confirms the monophyly of Galecyon and places it basal to Prolimnocyon, Prototomus, and Pyrocyon. Arfia is identified as the earliest diverging hyaenodontid sampled, contrasting with prior support for a more crownward position. Prototomus martis is more closely allied to Pyrocyon than to other species of Prototomus. The three North American species of Galecyon form a probable anagenetic lineage.

In contrast to the immense effort that has been put into the geological survey and stratigraphic study of the Neogene of Bocas del Toro region (Panama), little research has been done on the systematics of this region's rich gastropod assemblages. This is the first paper dealing primarily with the Bocas Neogene gastropod assemblages (Strombidae) since the pioneer work of Olsson (1922). Neogene strombid assemblages of the Dominican Republic have recently been reviewed and updated, and, therefore, the Strombidae are a suitable starting point for the revision of the gastropod assemblages from the Neogene of Bocas del Toro. Six species of Strombus are described, three of them new: S. acanthospira n. sp., S. pugiloides, S. gatunensis, S. elegantissimus n. sp., S. vermeiji n. sp. and S. cf. floridanus.

Tubular fossils, up to 2 mm in diameter and 60 mm in length, occur rarely in the upper Martinsburg Formation (Upper Ordovician), northeastern Tennessee Appalachians, U.S.A. The fossils are unbranched, straight or slightly bent, occasionally twisted and wrinkled, and not significantly tapered. Orientation of the fossils within shallow-marine tempestites suggests that they represent remains of organisms that were broken, transported, and deposited by storm waves and currents. The fossils are morphologically similar to many of the previously identified species belonging to the genus Sphenothallus, a relatively rare tube-dwelling Paleozoic marine invertebrate. Owing to the limited evidence for distal widening of the tubes, lack of holdfasts, and carbonaceous rather than phosphatic composition, the affinity of these fossils remains uncertain, and we refer to them as Sphenothallus-like.

The formal description of a liverwort from the Paraná Basin is presented. The fossil was found in the Rio Bonito Formation, Early Permian (Sakmarian), and is identified as a new species of the genus Hepaticites, named H. iporangae n. sp. The samples studied were collected from the macrofossil-rich roof-shale layer of the Quitéria Outcrop in the municipality of Encruzilhada do Sul, state of Rio Grande do Sul, Brazil. H. iporangae is one of the oldest liverworts reported from South America. The fossil described here provides more evidence of the relative diversity of liverworts in Paleozoic Gondwana despite the severe climatic conditions during the glaciations of the Permo-Carboniferous.

The Walcott-Rust Quarry echinoderm fauna lived at the base of a carbonate ramp in moderately deep water (Benthic Assemblage 5 of Boucot and others) below wave base for all or most storms but within the photic zone. The inhabitants of the soft substrate were buried rapidly by distal carbonate turbidity currents or mudflows. Because of the episodic sedimentation, the organisms were opportunistic. The suspension-feeding echinoderms include nine crinoids, a rhombiferan, and a paracrinoid. They occur with a variety of filter-feeding bryozoan colonies, a few brachiopods, and numerous trilobites. Most suspension-feeding echinoderms were attached by small holdfasts to hard shelly substrates. Some of these substrates lay on the seafloor, whereas others may have been elevated when the larvae settled. Other types of holdfasts are distal stems that are tightly and permanently coiled around crinoid stems, open distal stem coils that lay on the substrate or were wrapped around soft objects, and recumbent stems running along the seafloor. The echinoderms occupied levels from the seafloor to almost a meter above it, whereas the bryozoans and brachiopods ranged from the seabed to a maximum height of about 10 cm. The sizes of the echinoderm food grooves and comparisons with their modern analogues along with filtration theory indicate that they ate food particles that were mostly larger than those taken by bryozoans. In general, the different taxa of suspension-feeding echinoderms living at the same elevation above the seafloor collected food particles of different maximum sizes and different mean sizes; however, they overlapped greatly with respect to smaller food items. The various crinoid species were able to feed at different ranges of ambient current velocities, which also tended to separate them ecologically. Crinoids having narrow food grooves were restricted to feeding on small food particles but they caught food items over a wide range of current velocities; the converse is also true, which suggests an evolutionary or behavioral tradeoff. As in most Ordovician crinoid communities, predation was comparatively low. Regenerated arms in crinoids reflect predation on about 1.8% of the individuals in the fauna and the most likely fossilized culprits are trilobites and straight nautiloids. Competition for space and attachment sites within and between species of the Walcott-Rust Quarry crinoid and rhombiferan assemblages does not seem to have been significant in regulating their ecological structure. Comparison with shallow-water crinoid assemblages of roughly the same age demonstrates that the Walcott-Rust Quarry faunas were less diverse and less complex. This could be caused by one or more of the following conditions that affected the Walcott-Rust fauna: lower average current velocities, the episodic sedimentological disturbances, higher suspended sediment content in the water, and softer substrates.