Moroccodiscus smithi represents a new cyclocystoid genus and species based on moldic specimens from the Middle Ordovician Taddrist Formation (Darriwilian) of SE Morocco. This represents the earliest articulated member of the Cyclocystoidea and is the first complete cyclocystoid described from the Ordovician of Gondwana, as well as the first cyclocystoid ever recorded from Africa. The anatomy and morphology of this new species were studied using a combination of conventional paleontological methods and nondestructive X-ray computed tomography. Because Moroccodiscus differs from other cyclocystoids, in particular by lacking cupules attached to the marginal ossicles, it is assigned to the new family Moroccodiscidae. This new taxon illustrates the relatively poorly known early diversification of these enigmatic extinct echinoderms and sheds light on the mode of life of cyclocystoids, including injuries to plate circlets during early ontogeny and folding of these disk-like specimens at the time of death. The overall thecal shape was very similar in cyclocystoids and many domal edrioasteroids, probably because they were both sessile or attached, benthic, suspension feeders. However, many oral surface, ambulacral, and marginal ring features had become very different, indicating that these two groups had either converged because of similar life modes or were only distantly related sister groups.

Mickwitziids are a unique group of brachiopods, known exclusively from the Lower Cambrian. Herein are described the new species Mickwitzia lochmana and M. multipunctata; both species are from southwestern North America. Mickwitzia muralensis Walcott, 1913, the largest mickwitziid, is reported here for the first time from the United States. This paper also discusses the distribution of mickwitziids, their shell structure, and the possible functions of mickwitziid punctae.

The Roxton Limestone Member at the top of the Gober Chalk in northeast Texas yields a rich fauna, dominated by Baculites haresi Reeside, 1927, and Inoceramus balticus Boehm, 1909, with sparse occurrences of Pachydiscus cf. P. paulsoni (Young, 1963), Anapachydiscus sp. juv., Placenticeras placenta (DeKay, 1828), Hoplitoplacenticeras aff. H. plasticum (Paulcke, 1907), Menabites (Delawarella) delawarensis (Morton, 1830), M. (D.) danei (Young, 1963), M. (D.) aff. M. (D.) vanuxemi (Morton, 1830), Submortoniceras vandalinaense Young, 1963, Submortoniceras sp., Eubostrychoceras sp., and Scaphites hippocrepis (DeKay, 1828) III. The presence of S. hippocrepis III suggests a late early Campanian age assignment for the fauna. The assemblage includes species known from the Western Interior, Gulf Coast, Atlantic seaboard, and western Europe.

Arceodomus Pojeta and Runnegar (1976) is a relatively rare genus of rostroconch. To date, four species have been reported in the literature: A. langenheimi (Wilson, 1970) from the Lower Permian McCloud Limestone in California; A. glabrata (Easton, 1962) from the Upper Mississippian Heath Formation of Montana and later, by Pojeta and Runnegar (1976), from the Upper Mississippian Diamond Peak Formation of Nevada; Arceodomus sp. from the Permian of the U.S.S.R. (Pojeta and Runnegar, 1976), based upon a specimen in the British Museum of Natural History; and A. aff. A. glabrata from the Pennsylvanian (Desmoinesian) Dickerson Shale Member of the Lazy Bend Formation in Texas (Pojeta and Runnegar, 1976).

The Archaeopithecidae is a very poorly known group of native ungulates from the Eocene of Patagonia (Argentina), whose alpha taxonomy has remained obscure since Ameghino’s times. It is traditionally considered as a family representative of the Casamayoran (middle Eocene) South American Land Mammal Age, and is thought to be morphologically close to the notopithecids. After studying >200 specimens from several institutions, including all the type specimens, a taxonomic overestimation is established. Out of the six species considered originally as archaeopithecids, Archaeopithecus rogeri Ameghino, 1897 is here recognized as the only valid name and species; subsequent synonymies are proposed and previous taxonomic hypotheses discarded. This exhaustive revision has permitted improving the knowledge of A. rogeri and, for the first time, it has revealed many craniodental characters, which allow amending its diagnosis and differentiating this taxon from other Eocene notoungulates. Archaeopithecus rogeri is a small-sized taxon characterized by its complete and rooted dentition, which is relatively higher than that of other contemporaneous short-crowned notoungulates and shows ontogenetic variation in size and morphology. The body mass range of A. rogeri (1.4–2.5 kg) is comparable to those of notopithecids and some small hegetotheriids. The phylogenetic analysis shows A. rogeri is not directly related to any family within Notoungulata, appearing into a polytomy, as a basal taxon of typotherians. The biochronological range of A. rogeri is adjusted to Vacan (middle Eocene) through Barrancan subages (late middle Eocene); older (Riochican, late early Eocene) and younger (Mustersan, late Eocene) records remain to be confirmed.

Muscle scars are described for the first time in the Ordovician bellerophontoidean gastropod Carinaropsis Hall. Silica replicas from the Cannon Limestone of Tennessee preserve a pair of muscle scars, with a single elongate scar located on each umbilico-lateral angulation of the shell interior more than half a whorl back from the apertural margin. The scars are similar in general shape and position to muscle scars described in Bellerophon de Montfort and the pleurotomarioidean Porcellia woodwardi (Sowerby). In addition to supporting the soft parts within the widely expanded shell, the characteristic internal septum of Carinaropsis probably facilitated clamping of the shell aperture against the substrate.

Reinterpretations are made of North American Pennsylvanian rostroconchs based on shell form, shell structure, and surface ornamentation. The new family Pseudobigaleaidae, new genera Baiosoma, Hadropipetta, Exalloschema, Oxyprora, and Apotocardium are erected, and the new species Arceodomus angustus and Apotocardium plautum are recognized. Study of growth increments on Apotocardium lanterna (Branson) indicate annual and monthly growth rates and life span.

Thin sections studied provide insights into shell layer structure and thickness and variation in shell form. Characteristics of the protoconch and its relationship to body shell layers are illustrated. Epifaunal elements consisting of worm tubes, inarticulate brachiopods, acrothoracic barnacles, bryozoans, corals, and algae are present, some suggest attachment to the host rostroconch in life position.

Recent cladistic analyses have all suggested a diapsid origin of ichthyosaurs. However, an intermediate evolutionary stage of the lower temporal region of ichthyosaurian skull between basal diapsids and derived ichthyosaurs has been absent from the fossil record. Here we describe the cranial skeleton of a new mixosaurid ichthyosaur specimen with a well-preserved lower temporal region from the Anisian Guanling Formation of eastern Yunnan. It is characterized by the most primitive lower temporal region within known ichthyosaurs. The primitive characters of the lower temporal region include both external and internal separation between the jugal and the quadratojugal, an anterior process of the quadratojugal, an apparent posteroventral process of the jugal, and a large lower temporal opening surrounded by the jugal, the postorbital, the squamosal, and the quadratojugal. The lower temporal region of this specimen provides the most direct evidence to the diapsid origin of ichthyosaurs. It also suggests that the disappearance of the lower temporal fenestra is caused initially by the reduction of the lower temporal arcade rather than the enlargement of the surrounding bones.

The fossil record of Australasian Formicidae is extremely sparse. It currently comprises two ants in the subfamilies Ponerinae and Dolichoderinae from Plio/Pleistocene strata in Victoria, Australia, 14 as-yet undescribed ants from Cape York amber, and one ant in the subfamily Amblyoponinae from the early Miocene Foulden Maar in southern New Zealand. Here, we report on a diverse myrmecofauna preserved as compression fossils from Foulden Maar and describe Amblyoponinae gen. et sp. indet., Rhytidoponera waipiata n. sp., Rhytidoponera gibsoni n. sp., Myrmecorhynchus novaeseelandiae n. sp., and Austroponera schneideri n. sp. Further isolated wings are designated as Formicidae sp. A, B, and C, the former resembling a member of subfamily Dolichoderinae. Fossils of Austroponera and Myrmecorhynchus are reported for the first time, whereas Rhytidoponera waipiata n. sp. and R. gibsoni n. sp. are the first Southern Hemisphere fossil records of this genus.

The fossil taxa from Foulden Maar establish the subfamilies Ectatomminae, Formicinae, Ponerinae and, possibly, Dolichoderinae in the Australasian region in the early Miocene and provide evidence that the few native ants in the extant New Zealand fauna are the surviving remnant of taxonomically different, possibly more diverse, warm-temperate to subtropical myrmecofauna.

The Survey Peak Formation (350 m thick) consists of calcareous shale, mudstone, siltstone, and limestone-pebble conglomerate, and is formally divided into four revised members, successively: Basal Silty Member, Putty Shale Member, Middle Carbonate Member, and Upper Carbonate Member. The Wilcox Pass section, Jasper National Park, Alberta, provides a standard stratigraphic section for the southern Canadian Rocky Mountains and yielded over 4,500 conodonts from 87 samples which are of high species diversity, moderately well preserved, with a conodont Color Alteration Index (CAI) value of 3. Over 50 multielement species representing some 20 genera are identified, and most are illustrated. Conodont zones recognized in the four members include: Basal Silty Member—Eoconodontus notchpeakensis, Cordylodus proavus, C. caboti, C. intermedins, and C. lindstromi; Putty Shale Member—lower C. angulatus; Middle Carbonate Member—upper C. angulatus and coeval Rossodus manitouensis, Colaptoconus priscus (new) and Scolopodus cf. S. rex; Upper Carbonate Member—Striatodontus lanceolatus-S. striatus. In total, ten conodont lineage and assemblage zones are recognized within the Survey Peak Formation. Most can now be precisely correlated with trilobite faunas and acritarch microfloras described from this section, and with conodont zones established for the Great Basin area, Utah-Nevada, and for western Newfoundland. The Survey Peak Formation is of uppermost Cambrian to lower Ibexian (Tremadoc) in age with the Cambrian-Ordovician boundary placed between 26 and 29 m above the base of the formation in the Basal Silty Member.

The presence of Swiftopecten Hertlein, 1936, in Patagonia (Argentina), a region situated in the southeastern extreme of the South American continent, is the oldest and southernmost fossil record of the genus. Furthermore, its occurrence during the Late Eocene in the circum-Antarctic region suggests that its origin was in the Southern Hemisphere; it has been known from Japan and the eastern Pacific, ranging from Miocene to Holocene (Moore, 1984). Swiftopecten iheringii new species, from the Late Eocene-Early Miocene sedimentary sequence of Patagonia, is described and illustrated.

An almost complete specimen of the pentacrinid Seirocrinus subangularis (Miller, 1821) is described from the Red Deer Member of the Fernie Formation in the Rocky Mountains of central-western Alberta. Associated ammonites representing the Stokesi Subzone of the Margaritatus Zone indicate a Late Pliensbachian (Early Jurassic) age for the specimen. Taphonomic features suggest preservation in soft muds on a quiet, oxygen-deficient seafloor, so that the lower surface is preserved intact while ossicles on the exposed upper surface became disarticulated and were slightly disturbed. This occurrence in western Canada represents a major extension of the geographic range of the species.

One of the most severe restrictions in taxonomic diversity of trilobites coincides with the Late Devonian “Hangenberg” Event, which is characterized by a pronounced eustatic low-stand. One of the survivors of this event is Pudoproetus, which, being adapted to shallow water conditions, experienced an opportunistic worldwide spread during this time. The oldest representatives of this genus are reported from the pre-Hangenberg Late Famennian of the Urals and Kazakhstan. Other known occurrences of this genus, midcontinent U.S.A., Utah, southern China, and southern France, occur at the Devonian-Carboniferous boundary, shortly after the Hangenberg event, and in the earliest Carboniferous. This pattern of distribution suggests that neither climatic nor geographic migration barriers existed around the Old Red landmass at that time. On the other hand, the Hangenberg crisis severely affected outer shelf benthic habitats, whereas nearshore trilobites were largely unaffected by the event.

A proetine origin of Pudoproetus, as originally proposed by Hessler (1963), is emphasized on the basis of paleoecologic, stratigraphic, and morphological arguments. In particular, the presence of ancestral features, such as the possession of 10 thoracic segments and lateral occipital lobes still occurring in early Pudoproetus species, points to a phylogenetic link with proetines rather than with phillipsiids. Within this group two new species are named: P. priscus and P. mediterraneus.

Leperditiocope ostracodes identified as Sollenella? sp. were discovered in the Gilboa Formation (upper Givetian, uppermost Middle Devonian) within the continental Catskill Magnafacies of New York State. The deposits in which the ostracodes were found are meandering-fluvial facies that were part of a vast alluvial plain that sloped westward from the eroding Acadian Mountains. Hence, ostracodes colonized freshwater habitats earlier than heretofore thought. It has been widely accepted that, until now, the oldest known unequivocal occurrences of freshwater ostracodes are of Late Carboniferous age. This new discovery means that the first colonization of freshwater habitats by Ostracoda occurred approximately 60 million years earlier than previously known.

Upper dentition of Protosciurus mengi Black, from the Orellan Brule Formation, Nebraska, is described for the first time. The zygomatic plate is tilted anterodorsally, showing the beginnings of sciuromorphy as in the Arikareean species of this genus. A new genus of sciurid, Oligospermophilus, is named for the species originally identified as ?Protosciurus douglassi (Korth), based on additional material including a skull and upper dentitions. The zygomasseteric structure of O. douglassi is unlike any previously described Tertiary sciurid. The range of O. douglassi is extended from the late Chadronian to the Whitneyan. Three distinct lineages of sciurids, distinguished on dental morphology and zygomasseteric structure, can be traced in the Oligocene in North America; they are represented by the genera Protosciurus, Oligospermophilus, and ?Protosciurus.

The Cambrian trilobite Shantungia Walcott, 1905 is a monotypic genus, with S. spinifera Walcott, 1905 as the genotype and is characterized by its long frontal spine extending medially from the anterior cranidial border. The genus has hitherto been known restricted in occurrence to the traditional Drepanura Zone of North China (Walcott, 1913; Endo and Resser, 1937; Qiu et al., 1983; Zhang and Jell, 1987). As Drepanura Bergeron, 1899 is preoccupied by a collembolan insect and Neodrepanura Özdikmen, 2006 was proposed as a replacement, this zone is referred to as the Neodrepanura Biozone herein.

Representatives of the family Strephocladidae have been considered as fossil relatives (i.e., stem-group) of Mantodea (mantises) based on characters of the forewing morphology. Here we describe new specimens from the Wellington Formation that we assign to the strephocladid species Homocladus grandis Carpenter, 1966. The range of morphological variation exhibited by the new material, in addition to wing morphology variability documented in extant mantises and roaches, suggest that H. ornatus Carpenter, 1966 and Paracladus retardatus Carpenter, 1966, reported from the same formation, are new junior subjective synonyms of H. grandis. We describe the first hind wing for this species based on a well-preserved specimen. It exhibits a combination of character states unique to dictyopteran insects.

The specimens of Gastrochaena cuneiformis Spengler, 1783, with Spengler-written labels at the Zoologisk Museum, Copenhagen, did not come from Spengler's type locality in the Nicobar Islands, and may instead be syntypes of Chemnitz's (1788) West Indies “Pholas hians”. the identity of Gastrochaena cuneiformis as a senior synonym of Gastrochaena gigantea (Deshayes, 1830) is established on the basis of Spengler's original descriptions and illustrations, and by examination of specimens from the type locality. A neotype for G. cuneiformis is designated and illustrated, and its genus is revised to exclude Rocellaria Blainville, 1829, and Lamychaena Freneix in Freneix and Roman, 1979. Gastrochaena Spengler, 1783 is the most plesiomorphic of these three genera, as shown by its simple boring, short siphons, and diffuse, poorly differentiated anterior pedal muscles. Rocellaria evolved from a close common ancestor with Gastrochaena, and is characterized by a ventral shift and fusion of the posteroventral pallial sinus with the posteroventral pallial band, low, irregular posterior commarginal lamellae, and well defined anterior pedal retractor muscles generally supported by myophores. Lamychaena evolved from Rocellaria during the Oligocene, extending its ctenidia far posterior into the siphonal part of the boring, and, in some species, uniting its anterior pedal retractor and protractor muscles as they approach the byssus apparatus.

A moderately diverse crinoid fauna from the Early Mississippian, Tournaisian, part of the Bahram Formation is reported from exposures in the vicinities of Hutk and Shams Abad, north of Kerman in southeastern Iran. Conodonts from the crinoid-bearing beds represent two faunas and indicate an age of Upper Siphonodella crenulata Biozone to Gnathodus typicus Biozone. Recognition of a Tournaisian age for this part of the Bahram Formation revises the previously assigned Famennian age and indicates that Famennian strata are much thinner, if present, in southeastern Iran.

The fauna occurs in thin-bedded marls and limestones at the top of a shaley slope-forming sequence that grades upward into resistant cliff-forming limestones. Most crinoid specimens are crowns (many retaining part of the proximal stem) that have been flattened by compaction. At the genus level the crinoids include five camerates, three cladid dendrocrinids, ten other cladids, three flexibles, and one articulate. In addition, loose arm fragments and occasional cup fragments are common, along with abundant pluricolumnals and columnals in the fauna. Dominance of cladids over camerates probably reflects the argillaceous sediment in the mixed carbonate/siliciclastic platform environment of the fauna.

This is the most diverse Tournaisian fauna reported from the northern margin of Gondwana and represents an equatorial fauna living at approximately 20°S latitude. Stronger affinities are with North American and European crinoid faunas than with Chinese and Australian faunas. Shallow-shelf conodonts from the crinoid-bearing beds are dominated by species of Polygnathus. Palaeoniscoid fish remains and shark teeth from the same beds support a shallow-shelf environment.

New taxa proposed are Dichocrinus shamsensis new species; D. labyrinthus new species; Springeracrocrinus conicus new species; Atelestocrinus hutkensis new species; Zangucrinus abadensis new genus and species; Glossocrinacea new superfamily; Gelasinocrinus revimentus new genus and species; Amabilicrinidae new family; Amabilicrinus iranensis new genus and species, A. bahramensis new species; Derorhethocrinus elongatus new genus and species; Corematocrinidae new family; Lorocrinus zanguensis new genus and species; Blothrocrinus yazdii new species; Culmicrinus cylindratus new species; Paracosmetocrinus delicatus new species; Taxocrinus quadribrachiatus new species; Meristocrinus ovatus new species; and Hutkocrinus kermanensis new genus and species.

Revision of the Glossocrinidae also resulted in designation of two new genera not present in the Iranian fauna: Bufalocrinus new genus (type species Catactocrinus? torus Webster and Hafley, 1999, from the Late Devonian, Famennian, of Colorado) and Nudalocrinus new genus (type species Culmicrinus jeffersonensis Laudon and Severson, 1953, from the Tournaisian of Montana).

The upper part of the Santa Rosita Formation (Ordovician, Tremadocian) in the Nazareno area, Cordillera Oriental, northwestern Argentina, records the vertical passage of high-energy, shallow water platform environments to offshore settings. Eighteen trilobite species are described from this locality for the first time. Although the taxa from the lower part of the succession (Leptoplastides sp., Asaphellus sp.) are scarce and non-age diagnostic, those from the upper part include diverse assemblages partially assigned to the late Tremadocian Notopeltis orthometopa Zone. Systematic descriptions of several species (Geragnostus nesossii Harrington and Leanza, G. callaveiformis Harrington and Leanza, Asaphellus jujuanus Harrington, Notopeltis orthometopa [Harrington], Mekynophrys nanna Harrington, Ceratopyge forficuloides Harrington and Leanza, Apatokephalus tibicen Přibyl and Vanĕk) are improved, the genus Nileus Dalman (including N. australis n. sp.) is first reported from the Tremadocian of western Gondwana, and new species of Asaphellus Callaway (A. nazarenensis n. sp.), Conophrys Callaway, and Apatokephalus Brøgger are described. The trilobites have their closest affinities with faunas from Norway and Sweden. Notopeltis orthometopa and Mekynophrys nanna are restricted to the uppermost part of the succession, well above the first records of most other trilobites recognized.