Fenestrate microbialites from the 2521±3 Ma Gamohaan Formation, South Africa, are composed of calcite with traces of kerogen that represent the remains of ancient microbial mats. To delineate the 3-D geometry of these microbialites, specimens were serial-sectioned; sequential slices were polished in 120 μm increments and scanned to yield an image stack, which was rendered into a virtual model of the microbialites. The resulting virtual representation allowed for visualization and characterization of microbial growth geometries that were not visible from 2-D surfaces. Several new insights into the structure of microbialites emerged from characterizing their 3-D structure including the recognition of two new features, linear structures and tubular structures. The long, thin nature of these structures makes them difficult to identify in two dimensions. However, in three dimensions, they can be traced as thin ropes of fossilized microbial communities emerging from more typical microbial mat structures. Overall, these results demonstrate a new set of microbial features in the Gamohaan Formation that were only characterized by reconstructing the full geometry of the microbialites in three dimensions.

Records of abnormal fossil arthropods present important insight into how extinct forms responded to traumatic damage and developmental complications. Trilobites, bearing biomineralized dorsal exoskeletons, have arguably the most well-documented record of abnormalities spanning the Cambrian through the end-Permian. As such, new records of malformed, often injured, trilobites are occasionally identified. To further expand the documentation of abnormal specimens, we describe malformed specimens of Lyriaspis sigillum Whitehouse, 1939, Zacanthoides sp. indet., Asaphiscus wheeleri Meek, 1873, Elrathia kingii (Meek, 1870), and Ogygiocarella debuchii (Brongniart, 1822) from lower Paleozoic deposits. In considering these forms, we propose that they illustrate examples of injuries, and that the majority of these injuries reflect failed predation. We also considered the origin of injuries impacting singular segments, suggesting that these could reflect predation, self-induced damage, or intraspecific interactions during soft-shelled stages. Continued examination of lower Paleozoic trilobite injuries will further the understanding of how trilobites functioned as prey and elucidate how disparate trilobite groups recovered from failed attacks.

Additional fossil material from the Valentine Formation in Knox and Brown Counties, Nebraska, has allowed for the recognition of three new species of rodents, a heteromyid (Perognathus brevidens), a geomyid (Parapliosaccomys annae), and a zapodid (Schaubeumys cartomylos). The specimens referred here to P. brevidens were previously identified as P. furlongi, those of S. cartomylos were identified as S. grangeri, and those of P. annae were previously recognized as Lignimus cf. L. hibbardi. It is evident that Lignimus Storer should be restricted to the type species L. montis, and the remainder of the species referred to this genus are referred to Parapliosaccomys Shotwell. Parapliosaccomys is recognized as the earliest member of the subfamily Geomyinae based on its dental morphology, which extends the range of this subfamily into the Barstovian. The fauna from Annie's Geese Cross Quarry (Knox County) is recognized as being late Barstovian based on comparison with the older Norden Bridge Quarry (Brown County).

Uppermost temaikan strata from southwest Auckland Province, North Island, New Zealand, have recently yielded a small fauna of Middle Jurassic ammonites previously believed to be endemic to the eastern Pacific borderlands, although a single fragment of the new species described below was previously reported in a large Tethyan assemblage from Papua, New Guinea, by Westermann and Callomon (1988). The New Zealand assemblage consists of the dimorphic pair Xenocephalites (♂) and Lilloettia (♀) with close morphologic ties to species from the latest Bathonian Steinmanni Standard Zone of the Andean Province (Riccardi et al., 1989). This new find permits direct time-correlation of the uppermost part of the Temaikan Stage (Marwick, 1951, 1953) with the East-Pacific latest Bathonian Steinmanni Zone and with the East-Tethyan Late Bathonian Macrocephalites apertus Association. The upper Temaikan Stage of south Otago Province, southeastern South Island, New Zealand, has also yielded rare representatives of the Tethyan Macrocephalitinae, so that the New Zealand area in the late Middle Jurassic was in the overlap area of Tethyan and East-Pacific Subrealms.

Arthropleurids were terrestrial, millipede-like arthropods, The genus Arthropleura Jordan from the Upper Carboniferous reached an enormous size of 2 m or more in length (Hahn et al., 1986), Occurrences are rare and the chronologie and paleogeographic distribution of Arthropleura coincides with the tropical Euramerican floral belt of the Carboniferous (Rolfe, 1969), The Carboniferous was a time of high atmospheric O2 levels (35%) compared to the current 21%, which may have favored the development of large terrestrial arthropods of this time (Dudley, 1998; Graham et al., 1997; Berner, 2001) . Body fossils of Arthropleura range from the Visean to Early Permian (Rolfe, 1969; Schneider and Barthel, 1997), while trackways have been reported from the Visean (Pearson, 1992) to Stephanian (Langiaux and Sotty, 1977; Castro, 1997; Fig. 1). Arthropleura fragments have been described from Ohio, Pennsylvania, Illinois, and Nova Scotia. Only four Arthropleura trackway sites have been described from North America (New Mexico, Kansas, Nova Scotia, and New Brunswick). Trackways provide information about size and locomotion that is not discernable from fragmentary body fossils .

Two Upper Triassic sphinctozoan sponges of the family Sebargasiidae were recovered from silicified residues collected in Hells Canyon, Oregon. These sponges are Amblysiphonella cf. A. steinmanni (Haas), known from the Tethys region, and Colospongia whaleni n. sp., an endemic species. The latter sponge was placed in the superfamily Porata by Seilacher (1962). The presence of well-preserved cribrate plates in this sponge, in addition to pores of the chamber walls, is a unique condition never before reported in any porate sphinctozoans. Aporate counterparts known primarily from the Triassic Alps have similar cribrate plates but lack the pores in the chamber walls. The sponges from Hells Canyon are associated with abundant bivalves and corals of marked Tethyan affinities and come from a displaced terrane known as the Wallowa Terrane. It was a tropical island arc, suspected to have paleogeographic relationships with Wrangellia; however, these sponges have not yet been found in any other Cordilleran terrane.

A large, diverse, and well-preserved fauna of nonmarine mollusks has been recovered from the late Oligocene to early Miocene (Arikareean) fluviatile and lacustrine sediments that accumulated in four intermontane structural basins of western Montana. The Pupillidae are represented by 10 species, with nine new species and one new subgenus among three extant genera. The Gastrocopta are very diverse, with one new subgenus Ameralbinula represented by three new species, G. obesa, G. russelli, and G. oviforma, while three new species, G. tavennerensis, G. leonardi, and G. conica, are referred to the extant subgenus Vertigopsis Sterki, 1893. Gastrocopta miniscula cannot be referred to a subgenus with certainty. The remaining new species, Vertigo whitei and Pupoides montana, are referred confidently to extant subgenera. Vertigo arenula (White, 1876) is the only previously described species and its description is emended based on new material. The mammalian biostratigraphy of the Cabbage Patch beds is presented.

Nine agnostoid species from late Cambrian (Paibian: Steptoean) boulders from the Cow Head Group in western Newfoundland fall into three biostratigraphically distinct faunas. The Glyptagnostus reticulatus Fauna contains only the eponymous species and correlates with the lower part of the Paibian and the basal Steptoean of North America. The “Innitagnostus” inexpectans Fauna is more diverse and likely correlates into part of the lower Steptoean Aphelaspis Zone of western North America. The youngest fauna, the Acmarhachis kindlei n. sp. Fauna, also includes species of Homagnostus and Pseudagnostus, as well as a second new species of Acmarhachis, A. whittingtoni. It probably correlates with the Dunderbergia Zone (mid-Pabian and mid-Steptoean) of the western United States. The Laurentian species Acmarhachis typicalis Resser (1938) and A. acuta (Kobayashi, 1938) are evaluated from restudy of type material, and types of “Innitagnostus” inexpectans (Kobayashi, 1938) from British Columbia are also reillustrated.

Several biostratigraphically important gastropod genera are described from Alberta, British Columbia, Yukon Territory, and the District of Mackenzie. Malayaspira is present in the mid-Ibexian Kechika Group. Palliseria, Maclurites, Teiichispira, Malayaspira, Barnesella, and Ceratopea occur in the Skoki Formation (highest Ibexian and lower Whiterockian) and Helicotoma and Palliseria in the Sunblood Formation (lower Whiterockian). The largest known Teiichispira operculum is illustrated. The forms are particularly useful for age determination within relatively narrow limits and most of the taxa are readily identified in the field.

Collections from the basal part of the marine Eocene Tejon Formation, Tehachapi Mountains, southern California, reveal new stratigraphic occurrences of patellogastropod limpets. Reports of these gastropods from California Paleogene strata are uncommon. The Tejon limpets are all members of the tropical genus Patelloida. Four taxa are represented in 33 specimens from five localities. These taxa include: mature specimens of P. tejonensis (Gabb, 1869), the first occurrence of the Eocene P. vokesi (Hickman, 1980) outside of Oregon, and P. triquetrus n. sp., described herein. Our study shows that a hypotype referred to P. tejonensis by Anderson and Hanna in 1925 is actually a fissurelloidean species, and we tentatively reallocate it to the genus Megathura Pilsbry, 1890. Analysis of depositional settings indicates that nearshore, shallow-subtidal depositional environments have higher patellogastropod abundance and diversity than intertidal or offshore-subtidal depositional environments. Morphological convergence between Tejon and Recent patellogastropod taxa is documented. Resemblance of the Eocene P. triquetrus n. sp. and an indeterminate Patelloidea sp. to the Quaternary “Collisella” scabra (Gould, 1846) and Lottia digitalis (Rathke, 1833), respectively, is remarkable.

The Order Asaphida was grouped by the presence of a ventral median suture and a globular protaspis. The Superfamily Trinucleoidea has been assigned to the Order Asaphida, based on the recognition of a globular protaspis in the Ordovician representatives of the group, and the presence of a ventral median suture in the middle Cambrian genus Liostracina which has been regarded as a primitive sister-group to the post-Cambrian trinucleoideans. Recent studies demonstrate that the ventral median suture and the globular protaspis could have evolved multiple times in the trilobite evolutionary history, casting doubt on the traditional concept of the Order Asaphida. Inclusion of the Trinucleoidea into the Order Asaphida, therefore, has to be tested. It has recently been revealed that Liostracina simesi Jago and Cooper, 2005 did not possess a ventral median suture, implying that there could have been variable types of ventral suture within the genus Liostracina. Here we report the ontogeny of Liostracina tangwangzhaiensis n. sp. from the Cambrian Series 3 (middle Cambrian) strata of Shandong Province of North China. The material for this study includes protaspides, which are of flat, benthic morphology, contrasting to the globular protaspid morphology of the Ordovician trinucleoideans. The benthic protaspid morphology of L. tangwangzhaiensis indicates an independent evolution of the globular protaspis within the Superfamily Trinucleoidea. Together with the variable types of ventral suture within the genus Liostracina, the benthic protaspid morphology of Liostracina leads us to propose that the Superfamily Trinucleoidea be excluded from the Order Asaphida.

A large number of well-preserved immature exoskeletons enable the first detailed quantitative description of the ontogeny of the trinucleid Marrolithus bureaui (Oehlert, 1895) from the Lower Caradoc of the Armorican Massif (Armorica, northwest France). For the accurate description of cephalic features, a landmark-based approach was adopted in order to recognize ontogenetic instars and to establish the patterns of size increase and shape change during ontogenetic development. The quantitative analysis permitted the demonstration of a progressive shape change in agreement with ontogenetic ordination and a comparison of the timing of size and shape changes. Changes that took place during the meraspid period included, in particular, the development of a more pronounced sub-quadrangular cephalic outline, a compression (sag.) of the glabella and a size decrease until disappearance of the alae in late stages. This quantitative ontogenetic reconstitution of Marrolithus bureaui might be considered as a reference for the better understanding of phylogenetic affinities between other trinucleid species.

A complete molted exoskeleton of the asteropygine phacopid trilobite Greenops widderensis Lieberman and Kloc, 1997 from the Middle Devonian (Givetian) Widder Formation in southwestern Ontario, Canada that has suffered predatory trauma provides insights into the sequence of regeneration of segments. The molt configuration is such that it is possible to interpret the molting technique used by the trilobite. Predatory trauma affected four areas of the exoskeleton. The pygidium shows loss of the spinose margin on one side and damage to a single spine on the other; one genal spine has been broken and partially regrown; and the posterior of the glabella has been removed. It is thought that the first three traumas occurred during life, as these areas affected show signs of exoskeletal regeneration. The fourth trauma probably occurred to the exuvium. Analysis of the degree of regeneration of the pygidial pleurae indicates that there was an anteroposterior polarity to the regeneration. Other examples in the literature suggest that this regeneration polarity pattern may have been widespread in trilobites. It is suggested that, as in modern arthropods and annelids, this sequential regeneration was under the control of segmentation polarity genes.

The presence of large numbers of phragmocones of Eutrephoceras and Aturia in an upper Eocene beach deposit of the La Meseta Formation on Seymour Island is the first known occurrence of beach-drifted accumulations of nautilid shells in the fossil record and may also represent the first documentation of a mass stranding of nautilids in the Cenozoic.

A new species in the extant genus, Hydrotrupes Sharp, H. prometheus n. sp., (Coleoptera, Dytiscidae) is described from Baltic amber (Eocene) based on examination of a single female specimen. This description represents one of a limited number of diving beetle taxa described from fossiliferous amber and is currently the oldest known fossil assigned to Agabinae. Based on this specimen Hydrotrupes is at least 40 million years old. The occurrence of Hydrotrupes during the Eocene suggests that the current disjunct distribution of living Hydrotrupes species occurring in western North America and eastern China is a relict of former widespread distribution in the northern continents. Considering the age of this fossil and its similarity to living members of the genus Hydrotrupes, the conservation of morphology in this lineage of diving beetles is notable. Key morphological characters of the new species are illustrated, and the significance of this discovery for understanding Agabinae evolution and the biogeography of this previously hypothesized trans-Beringian lineage is discussed.

A primitive paromomyid plesiadapiform primate, Edworthia lerbekmoi new genus and species, is described from a recently discovered locality in the Paskapoo Formation, exposed at a road cut in Edworthy Municipal Park, Bow River Valley, Calgary, Alberta, Canada. The new taxon, probably middle Torrejonian (To2) in age, is based on two dentary fragments containing well-preserved dentitions that bracket p2-4, m1-3. With the exception of the basal Paromomys, E. lerbekmoi differs from all other paromomyids in retaining p2, but p2 in the new paromomyid is single-rooted, not two-rooted as in Paromomys. E. lerbekmoi differs further from Paromomys in having an enlarged anterior alveolus for a tooth immediately anterior to p2, hypothesized to be il. Unlike other paromomyids with an enlarged il, however, this tooth in E. lerbekmoi was obliquely, not horizontally, oriented and its alveolus opens dorsally, in the alveolar row, not anteriorly, as in other paromomyids in which il is greatly enlarged. This suggests that E. lerbekmoi represents a previously unknown paromomyid lineage that evolved from an ancestor having obliquely oriented lower incisors as in the basal primate Purgatorius, not from an ancestor in which il was already subhorizontal in orientation, as in Paromomys. If this working hypothesis is correct or whether in the future some other evolutionary scenario will better account for the unique anterior dentition in E. lerbekmoi, the new paromomyid nonetheless demonstrates that crucial aspects of the earliest history of the important plesiadapiform family Paromomyidae remain to be discovered.

The external morphology and its variability, myocardinal apparatus, and shell structure of both valves of the radiolitid rudist Eoradiolites plicatus (Conrad) are described, based on the examination of about one hundred well-preserved, fairly complete specimens that are free of sediment matrix, found in a single bed of an ammonite-bearing Albian succession ('Knemiceras beds', Zebbag Formation) in central Tunisia. This study provides the most nearly complete knowledge of any Eoradiolites species to date. With this background, all previous records of E. plicatus, as well as the taxonomic status of the other Albian species of the genus, are revised considering both original material, when available, and published papers. As a result, the systematics of Eoradiolites is simplified.

The Permian is regarded as one of the most crucial intervals during echinoid evolution because crown group echinoids are first widely known from the Permian. New faunas provide important information regarding the diversity of echinoids during this significant interval as well as the morphological characterization of the earliest crown group and latest stem group echinoids. A new fauna from the Capitanian Lamar Member of the Bell Canyon Formation in the Guadalupe Mountains of West Texas comprises at least three new taxa, including Eotiaris guadalupensis Thompson n. sp. an indeterminate archaeocidarid, and Pronechinus? sp. All specimens represented are silicified and known from disarticulated or semiarticulated interambulacral and ambulacral plates and spines. This assemblage is one of the most diverse echinoid assemblages known from the Permian and, as such, informs the paleoecological setting in which the earliest crown group echinoids lived. This new fauna indicates that crown group echinoids occupied the same environments as stem group echinoids of the Archaeocidaridae and Proterocidaridae. Furthermore, the echinoids described herein begin to elucidate the order of character transitions that likely took place between stem group and crown group echinoids. At least one of the morphological innovations once thought to be characteristic of early crown group echinoids, crenulate tubercles, was in fact widespread in a number of stem group taxa from the Permian as well. Crenulate tubercles are reported from two taxa, and putative cidaroid style U-shaped teeth are present in the fauna. The presence of crenulate tubercles in the archaeocidarid indicates that crenulate tubercles were present in stem group echinoids, and thus the evolution of this character likely preceded the evolution of many of the synapomorphies that define the echinoid crown group.

Four species belonging in Tudiclidae and one in Melongenidae have been confused with perissityids. The new genus Rapopsis is proposed for a tudiclid species, R. joseana n. sp. of early Maastrichtian age. Three other tudiclid species may belong in the Tethyan genus Pyropsis, P. fantozzii n. sp. of early to middle Paleocene age, P. striata (Stanton, 1896) of later Paleocene age, and ?P. gabbi (Stanton, 1896) probably of early to middle Paleocene age. The melongenid genus Protobusycon, represented by P. judithae n. sp. of late Paleocene age, has not previously been recognized in eastern Pacific faunas.

An unusually complete large pycnodont fish from the Mooreville Chalk of Green County, Alabama, is figured and compared to several previously described specimens. Material from the specimen apparently places Grypodus Hay = Ancistrodon Roemer, Hadrodus Leidy, and Propenser Applegate into synonymy. The specimen is referred to Hadrodus hewletti (Applegate). A complete dentition is present and most of the thick, tuberculated ganoid scales that covered the body are preserved. Exact location of the dorsal fin has been determined and many of the fragile gill rakers are represented.