Three novel features are described in steinkerns of Hypomphalocirrus rugosus Linsley from the Middle Devonian Rogers City Limestone of Michigan. The first feature is located about one-half a volution adapertural of the terminal septum. It has the appearance of a typical molluscan muscle attachment scar and is interpreted as such. The two other features are more enigmatic. They have a less stereotyped appearance and location. The first is interpreted as a field of mantle point-attachments and the other as a product of partial shell dissolution. Comparisons with extant and fossil molluscs confirm that the two features ascribed to biologic origins are within the scope of molluscan soft-part and shell attachment morphologies.

Wrangellia was one of the first described and probably the most widely known of the North American Cordilleran terranes. On the basis of Triassic stratigraphy (Jones et al., 1977) and paleomagnetism (Hillhouse, 1977), the name Wrangellia was proposed for large areas of outcrop in Alaska, British Columbia, and Oregon (Fig. 1).

Two new species of the rhynchonellid brachiopod Probolarina are described, Probolarina neoleonensis new species and Probolarina papalotensis new species. They were collected from a Paleocene limestone lens associated with a diapir in the La Popa basin, northeastern Mexico. Thousands of these brachiopods occur in this lens and constitute the first report of brachiopods for the Difunta Group, from which a diverse paleobiota has been previously reported. This occurrence represents the oldest record for the genus in the Western Hemisphere, as the only other Paleocene occurence of this genus was reported from New Zealand. Recent studies suggest that the carbonate lentil from which the brachiopods were collected were deposited in the shadow-effect area adjacent to the diapir, which affected the sediment influx into the basin.

The pseudorthoceratid subfamily Macroloxoceratinae Flower, 1957, comprises a rare group of nautiloid cephalopods homeomorphic with the Actinoceratida in the development of a siphonal canal system. With the exception of Macroloxoceras Flower, 1957, from the Upper Devonian of Colorado and New Mexico, this subfamily has previously been reported only from the Mississippian of Europe. A specimen described herein from the late Viséan–?early Namurian Kennetcook Limestone of the Windsor Group of Nova Scotia, assigned to Campyloceras cf. C. unguis (Phillips, 1836), extends the range of the Macroloxoceratinae into the North American Mississippian. This discovery further provides new data on the complex siphonal morphology of this poorly known group of nautiloids, and supplements the recent documentation of the pseudorthoceratids in the Windsor Group cephalopod fauna (Edgecombe, 1987).

Strata of the Solvik Formation in the central Oslo Region (upper Hirnantian through most of Aeronian) are very fossiliferous and provide a good record relating to the survival and recovery faunas after the end-Ordovician mass extinctions. The ribbed atrypide fauna is especially rich with 21 species present. Samples from most of these taxa have been sectioned to reveal internal structures for taxonomic study. Of these, 13 species belong to the family Atrypidae, three of which are described in the present paper; Dihelictera engerensis n. sp., Gotatrypa vettrensis n. sp., and Rhinatrypa henningsmoeni n. gen. The family Atrypidae follows a global pattern of recovery with an increase in diversity registered in upper Rhuddanian and further diversification in Aeronian strata. The focus of this paper is the family Atrypinidae, which shows a different pattern. They are common and fairly diverse near the base of the Rhuddanian in deeper waters and rare further up, especially in the Aeronian. One new genus, Bockeliena, and two new species, Plectatrypa rindi and Euroatrypa? sigridi are defined. The relationship between the subfamilies Spirigerininae and Plectatrypinae is clarified through thin sections of material from the Ordovician/Silurian boundary layers. The plectatrypids originated in Baltica through transitional species found in upper Katian to Hirnantian strata leading from the cosmopolitan Eospirigerina to the Plectatrypa lineage with imbricate ribbing and, separately, to Bockeliena and others with lamellose, widely spaced ornamentation. The Oslo Region probably acted as a nexus for survival and spread of brachiopods after the end-Ordovician mass extinction.

UUID: http://zoobank.org/95340b41-5537-4192-9338-211a2940bea8.

We describe a new extinct spiny rat, Proclinodontomys dondasi n. gen. n. sp. (Rodentia, Caviomorpha, Echimyidae), represented by a noteworthy preserved skull and mandible from the early-middle Pleistocene outcrops at the coastal cliffs of SE Buenos Aires Province (Central Argentina). Phylogenetic analyses allow us to propose that the new species described here and the already known Eurzygomatomys mordax (Winge) represent a new genus closely related to the living Euryzygomatomys spinosus and Clyomys laticeps. The new genus differs from Euryzygomatomys and Clyomys by having much more procumbent upper incisors, a more developed fossa for the M. temporalis, more flared and laterally expanded zygomatic arches, frontal less markedly expanded posteriorly, jugals much deeper anteriorly than posteriorly, with the dorsal border descending more abruptly posteriorly, smaller orbital cavity, and external auditory meatus relatively smaller and slanted upward and backward. Several features of the new species reflect a higher degree of adaptation to semifossorial habits than those of E. spinosus. The origin of the semifossorial ecomorphotype within echimyids may have been triggered by the expansion of relatively open and arid environments that arose near the Miocene-Pliocene boundary. The record of this new echimyid in Central Argentina indicates that during the early-middle Pleistocene, the southern limit of the geographic range of extinct representatives of the Brazilian lineage of semifossorial echimyids extended farther south than that of their living members.

UUID: http://zoobank.org/c30ec1fe-4352-4867-a02f-e0d45c884bfe

Lungfish are a poorly represented component of the Mesozoic fossil record in North America, as most lungfish fossils consist of rare, isolated dental plates that are of little diagnostic value due to their conservative nature. In eastern North America, the paucity of lungfish fossils in Late Cretaceous strata is further compounded by the occurrence of geologic units that are primarily marine in origin, unlike the Late Jurassic to mid-Cretaceous fluvial deposits of the American west that contain comparatively more specimens. Lungfish fossils from the eastern side of the Late Cretaceous Western Interior Seaway (Appalachia) have previously been reported from the Cenomanian Woodbine Formation of northeast Texas and the Campanian Mount Laurel Formation of New Jersey. Here we report two new occurrences of eastern North American lungfish tooth plates from the Santonian Eutaw Formation of Alabama and Mississippi. These two specimens are referred to Ceratodus frazieri Ostrom, 1970 and Ceratodus carteri Main et al., 2014, species that are better known from the mid-Cretaceous of the Western Interior of North America. This discovery is the first published record of lungfish of any age from the states of Alabama and Mississippi. It partially bridges the temporal gap in the fossil record between the Cenomanian lungfish of Texas and the Campanian lungfish of New Jersey and extends the biogeographic range of Late Cretaceous lungfish to the eastern Gulf Coastal Plain of the United States.

Non-archosaur archosauromorphs are a paraphyletic group of diapsid reptiles that were important members of global Middle and Late Triassic continental ecosystems. Included in this group are the azendohsaurids, a clade of allokotosaurians (kuehneosaurids and Azendohsauridae + Trilophosauridae) that retain the plesiomorphic archosauromorph postcranial body plan but evolved disparate cranial features that converge on later dinosaurian anatomy, including sauropodomorph-like marginal dentition and ceratopsian-like postorbital horns. Here we describe a new malerisaurine azendohsaurid from two monodominant bonebeds in the Blue Mesa Member, Chinle Formation (Late Triassic, ca. 218–220 Ma); the first occurs at Petrified Forest National Park and preserves a minimum of eight individuals of varying sizes, and the second occurs near St. Johns, Arizona. Puercosuchus traverorum n. gen. n. sp. is a carnivorous malerisaurine that is closely related to Malerisaurus robinsonae from the Maleri Formation of India and to Malerisaurus langstoni from the Dockum Group of western Texas. Dentigerous elements from Puercosuchus traverorum n. gen. n. sp. confirm that some Late Triassic tooth morphotypes thought to represent early dinosaurs cannot be differentiated from, and likely pertain to, Puercosuchus-like malerisaurine taxa. These bonebeds from northern Arizona support the hypothesis that non-archosauriform archosauromorphs were locally diverse near the middle Norian and experienced an extinction event prior to the end-Triassic mass extinction coincidental with the Adamanian-Revueltian boundary recognized at Petrified Forest National Park. The relatively late age of this early-diverging taxon (Norian) suggests that the diversity of azendohsaurids is underrepresented in Middle and Late Triassic fossil records around the world.

UUID: http://zoobank.org/e6eeefd2-a0ae-47fc-8604-9f45af8c1147.

The camerates, Pycnocrinus argutus (Walcott, 1883) and Rhaphanocrinus subnodosus (Walcott, 1883), are characterized by narrow food grooves. An open distal stem coil was present in P. argutus, and R. subnodosus may have possessed the same type of holdfast. Such holdfasts either lay loose on the seafloor or were wrapped around unknown soft objects. The rhaphanocrinids were located at elevations of at least 300 mm above the substrate. Conversely, the much smaller pycnocrinids lived close to the seafloor at levels of about 10 to 24 mm. The three cladids are Merocrinus curtus (Ulrich, 1879), M. retractilis (Walcott, 1883), and Dendrocrinus gregarius Billings, 1857a. Merocrinus typus Walcott, 1883 and M. corroboratus Walcott, 1883 are conspecific with M. curtus. The spiral anal sac of M. retractilis is unique. Embryocrinus problematicus Hudson, 1918 probably represents a juvenile of Dendrocrinus gregarius, which also occurs in Ottawa, Ontario. Complete columns and attachment structures have not been found for D. gregarius and Merocrinus retractilis. Merocrinus curtus ranges from New York into the Cincinnati, Ohio area of the midcontinent. Although attachment devices and long stem segments are not preserved in the New York specimens, individuals of Merocrinus curtus from Cincinnati either have a conical holdfast cemented to a bryozoan or a tight distal stem coil that was wrapped around the stem of another crinoid; adult merocrinids from the Cincinnati region were positioned high above the seafloor, and incomplete stem segments up to about 800 mm long are known. The Walcott-Rust Quarry cladids all possessed wider food grooves than the camerates, so they were able to catch larger food particles.

Antiquatonia sulcata Cooper was described from the Lower Permian Coyote Butte limestone of central Oregon (Cooper, 1957, p. 35, Pl. 5C, figs. 18–22). The name sulcata, however, was previously applied by J. Sowerby (1822, p. 17, Pl. 319, fig. 2) to Productus sulcatus from the Upper Visean of Great Britain, revised by Muir-Wood (1928). The British species has now been considered to be congeneric with Antiquatonia Miloradovich (Sarytcheva and Sokolyskaya, 1952, p. 148; Muir-Wood and Cooper, 1960, p. 271; Litvihovich, 1962, p. 250; Zakowa, 1988, p. 57). The two forms are sufficiently different in external features to be separated as two species under Antiquatonia. Antiquatonia sulcata of Cooper consequently becomes a later homonym of A. sulcata (Sowerby). The author has been kindly asked (G. A. Cooper, personal commun.) to offer a replacement name, Antiquatonia cooperi, for Cooper's A. sulcata (non Sowerby). Description and comparison of the Oregon species and its holotype has been provided by Cooper (1957, p. 35).

Review of collections in Prague and at Harvard University, supplemented by additional field observations, has allowed taxonomic updating and revision of Barrandian trinucleid trilobites. Genera identified are Bergamia, Declivolithus, Nankinolithus, Tretaspis, Marrolithus, Deanaspis, and Onnia. One earlier described species is assigned to the new genus Marekolithus.

Although partly isolated from the rest of north Gondwana during the Ordovician, the Prague Basin shares faunas with Sardinia and Morocco, as all show the transition from Deanaspis to Onnia. Spain, Britain, and the Baltic also share some species with Bohemia, particularly in the high Caradoc and Ashgill (Bohdalec and Králův Dvůr Formations).

Low to moderately highly-diverse ostracode assemblages containing a total of 49 taxa occur in the Imo Formation (Mississippian, Chesterian) in north central Arkansas. The less diverse assemblages are dominated by the platycope Cavellina, while the more diverse are dominated by the palaeocopes Hollinella, Gortanella, Amphissites, Sargentina, and Deloia; the leiocopes Proparaparchites and Shivaella; and the metacopes Healdia and Healdioides. The change in assemblages up section in the central portion of the formation indicates a deepening of water with variations in the amount of influx of terrigenous clastics in a nearshore marine environment.

New taxa described include Aechminella prostata, Cornigella laterispinosa, Hollinella (H.) imoensis, H. (H.) denotata, Pseudokegelites dorsopeltatus new genus and species, Polytylites oblongus, Glyptopleuroides inregularis, Oliganisus amictus, Doricranos incohatus new genus and species, Knoxina sohni, Proparaparchites ignotus, Shivaella juxarecta, Orthobairdia redacta, Monoceratina arkansasana, Healdioides retusus, H. commensuratus, Seminolites orthapsis, Venula elegantula, Prodigious rostratus new genus and species, and Microcheilinella? lenticularis.

The presidential address for The Paleontological Society traditionally has been given on a topic in the president's own special area of research. This year I am breaking that tradition because there are serious matters concerning this Society that deserve widespread discussion.

In central Chiapas (southeastern México) the last occurrence of inoceramid bivalves was recorded in strata of the predominantly terrigenous Ocozocoautla Formation. The inoceramids are associated with foraminifers of the Gansserina gansseri Zone (Late Campanian to Early Maastrichtian). The described species are: Cataceramus? cf. barabini (Morton, 1834), Cataceramus? cf. subcircularis (Meek, 1876), Trochoceramus aff. costaecus (Khalafova, 1966), Trochoceramus nahorianensis (Kociubynskij, 1968), and Trochoceramus tricostatus n. sp. Based on the inoceramid and foraminifer species present, the assemblage is assigned to the Early Maastrichtian. This age is important because at this level most of the typical inoceramids globally disappeared. This is the first report of the genus Trochoceramus in México, which is a good index fossil for the Early Maastrichtian and has a cosmopolitan distribution.

Records of fossil decapod crustaceans from Iran are scarce. Förster and Seyed-Emami (1982) reported Eryma bedelta (Quenstedt, 1857) from the Aalenian (Middle Jurassic) in northern Iran. Garassino and Krobicki (2002, p. 56) noted the presence of the lobster Eryma von Meyer, 1840, from Iran. Garassino (personal commun., 2005) confirmed that this referred to the work of Förster and Seyed-Emami and noted that this was the only decapod occurrence in the country known to him. Toraby and Yazdi (2002) reported a portunid from the Miocene of the country in an abstract but we are unaware of a subsequent publication. Microcoprolites with an internal structure characteristic of decapods are known from the Jurassic of Iran (Brönnimann, 1977). Thus, the discovery of the remains of a remarkable macrurous decapod, recovered from a well core sampling the Gadvan Formation, is noteworthy. This unique specimen is the basis for description of a new family, genus, and species of palinuroid lobster.

The Platteville crinoid fauna of northeastern Iowa consists of six species: Abludoglyptocrinus charltoni (Kolata, 1975), Carabocrinus sp. Kolata, 1975, Cupulocrinus plattevillensis Kolata, 1975, Ectenocrinus simplex (Hall, 1847), Merocrinus britonensis Kolata, 1975, and Porocrinus pentagonius Meek and Worthen, 1865. Other echinoderms include an unidentified cyclocystoid and several rhombiferan and crinoid plates. the echinoderms are mostly associated with a variety of passive suspension and filter feeders, principally brachiopods and bryozoans. Complete crowns and columns are available for the porocrinid and cupulocrinid, which lived at elevations of 28 and 50–60 mm above the seafloor, respectively. Although entire stems are not preserved, specimens from other stratigraphic units suggest that Abludoglyptocrinus charltoni, Ectenocrinus simplex, and Merocrinus britonensis occupied higher areas above the seafloor. the elevation of the carabocrinid is not known. the cyclocystoid was located on the seafloor. the crinoids are ecologically separated in two ways: different elevations above the substrate and food groove width, which is correlated with the size of the food items taken. the high-level crinoids mainly ate a narrow range of small items. However, the crinoids at lower levels caught many larger food particles and utilized a much wider range of food sizes. Cup growth of Cupulocrinus plattevillensis is isometric except for the heights of the infrabasals and radials, which exhibit significant positive and negative allometry relative to overall size. the proximal brachs are strongly allometric in which the widths increase much more rapidly than the heights.

A new species of chiton is described from early Miocene deposits of the Monte León Formation, in Santa Cruz Province, Argentina. Callochiton monteleonensis n. sp. clearly differs from known fossil and Recent species of the southwestern Atlantic because the central area of its intermediate valves has a stepped appearance, in which each step is marked by a longitudinal rib. It is similar to Callochiton kapitiensis Mestayer, 1926, a Recent species from New Zealand. Biogeographic implications are discussed. This is the first record of a polyplacophoran from Neogene deposits of Argentina.

In 1988, the presence of an Early Pennsylvanian ammonoid assemblage within the basal meter of the Callville Formation (Pennsylvanian-Permian), eastern Clark County, Nevada, was brought to the attention of the author by Stephen M. Rowland, University of Nevada-Las Vegas. The ammonoids occur in the Frenchman Mountain section described by Rowland (1987) for the Geological Society of America's Decade of North American Geology (DNAG) field trip compendium. The mid-Carboniferous section at this locality (Figure 1) was discussed in two other field trip guides as well (Langenheim and Webster, 1979; Webster et al., 1984). No ammonoids have been reported previously from this locality. Although this is the first record of Cancelloceras from the Great Basin region, the assemblage also provides a narrowly constrained age for the basal part of the Callville Formation at Frenchman Mountain, which in turn, dates the initiation of carbonate deposition following a major mid-Carboniferous hiatus in the southern Great Basin.