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).

Sinothemis difficilis new genus new species, youngest and first accurate Chinese representative of the small family Selenothemistidae, is described and illustrated. It is closely related to the genus Turanothemis, known from the Karatau outcrop in Kazakhstan. The genus Caraphlebia, known from the Middle Jurassic of Antarctica, seems to strongly differ from the other representatives of this family and may belong to another family. The fossil was collected from the Upper Jurassic (157.3 ± 1.5 Ma; near Oxfordian/Kimmeridgian boundary) Guancaishan locality, Jianping County, Western Liaoning, NE China. It belongs to the late assemblage of the Yanliao biota, while the early assemblage is represented by the putatively close damsel-dragonfly Paraliassophlebia from the Jiulongshan Formation of northern Hebei Province.

UUID: http://zoobank.org/8b11b148-852e-4079-a9fb-1884bf4b6d94

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

Approximately 10,000 determinable specimens of Pentremites pulchellus Ulrich (Blastoidea, Echinodermata) from a single quarry in the Pella Formation near Oskaloosa, Mahaska County, Iowa, have been examined for abnormal morphologic characters. The total frequency (2.7%) and the frequency among different types of abnormalities (ambulacral 29%; basal 46%; symmetrical 12%) are significantly different in the Pella material than in previously published studies (Wanner, 1932; Macurda, 1980). The greater frequency of abnormalities in the Pella Formation than in previous studies may reflect higher environmental stress because of variable temperatures or salinities or both. The kinds of abnormalities are the same among published studies, which suggest that the underlying biological causes of abnormalities were similar throughout the geologic history of the blastoids. Ambulacral abnormalities are symmetrically distributed, but the division and inversion of basal plates show an asymmetrical distribution as previously recorded by Macurda (1980). The Pella Formation is of Genevievian age (Upper Mississippian) based on the occurrence of Pugnoides ottumwa (White) and convex ambulacra in Pentremites pulchellus. Other unequivocal guide fossils are unknown in the Pella Formation.

Pollen extraction from sediments of the arid Southwest often involves a variety of problems, including low concentration and poor preservation of pollen, but particularly the complexing of soil particles and evaporites such as calcium carbonate (calcite) and calcium sulfate (gypsum) with the pollen. The low pollen concentration and particle complexing problems are overcome by extraction of a larger volume of sediment (normally 350–450 cc) than is typical for lakes and bogs of temperate regions. Dilute HCl dissolves the most common evaporite, calcium carbonate, and coarser silicates are then removed by sieving or swirling (Funkhauser and Evitt, 1959), thus concentrating finer silts, clays, clay-sized particles, and pollen. The finer silicates are subsequently removed by HF treatment. However, if the calcium ions are not removed completely, prior to the HF treatment, a precipitate of calcium fluoride forms which obscures pollen in the sample.

Hispanosinuites peeli new genus and species from the Lower Oretan shales (Middle Ordovician) of central Spain is described and placed in the new subfamily Hispanosinuitinae of the family Sinuitidae. This new subfamily is considered to represent a highly specialized phylogenetic lineage, which probably separated from the morphological range of the genus Sinuites during the Early Ordovician. The outer shell surface of Hispanosinuites peeli is entirely covered by secondary shell layers, which are interpreted as perinductura, inductura and coinductura. The similarity of these shell deposits in Hispanosinuites peeli and species of Euphemites suggests that these layers were secreted by mantle flaps having the same form in both genera. Hispanosinuites peeli is interpreted as a mobile mollusc with an internal shell adapted to an infaunal mode of life. Discovery of this unusual mollusc reopens the question of the phylogenetic relations of the families Sinuitidae and Euphemitidae, which are often assigned to different molluscan classes.

Chiniquodontidae is a family of nonmammaliaform probainognathian cynodonts with occurrences in the Middle to Late Triassic of Africa and South America (Brazil and Argentina). The history of the family is marked by changes in composition and revisions due to the poor preservation of the first discovered specimens. Currently, Chiniquodontidae includes two genera and six species. Here, we apply the computed tomography (CT-scan) method to describe and revise the morphology of one of the best-preserved chiniquodontid specimens (MCP 1600 PV, holotype of ‘Probelesodon’ kitchingi Sá-Teixeira, 1982) from Brazil, which allowed the visualization of sutures and the segmentation of each bone. The CT-scan data also revealed some previously undescribed traits due to the presence of matrix covering structures of the skull. In addition, the morphological comparisons revealed differences of MCP 1600 PV in relation to the other chiniquodontids, and eight discrete cranial features not related to ontogeny indicate that ‘Probelesodon’ kitchingi might not be included within Chiniquodon theotonicus Huene, 1936. Therefore, we consider the species valid but propose the new combination Chiniquodon kitchingi. Moreover, the results obtained highlighted the necessity of a reassessment of the family, as well as the description of new specimens, morphometric analyses, and use of CT-scan, when feasible.

We report three isolated humeri of small-sized parareptiles, which represent two different taxa, from the lower Keuper (Erfurt Formation) of Germany. They constitute the first definitive evidence of parareptiles in the lower Keuper. The specimens represent the first records of an owenettid procolophonian (aff. Barasaurus) from Europe and of a putative gracile-built procolophonid. This indicates the coexistence in the Middle Triassic of Germany of two procolophonian lineages that first appeared in the fossil record in the late Permian and survived the Permian–Triassic extinction. Although based on isolated limb bones, they highlight the taxonomic diversity of the still poorly known tetrapod assemblage of the lower Keuper in southwestern Germany.

The rugose corals described in this study were collected from the Gyanyima section in the Ngari region of southwestern Tibet (Xizang) and are assigned to three genera and 11 species, including a new genus and seven new species: Waagenophyllum (Waagenophyllum) ngariense He, 1990; W. (W.) elegantulum He in Luo et al., 1989; W. (W.) minutum Zhao, 1981; W. (W.) tachtabulasicum Ilyina, 1997; W. (W.) gyanyimaense n. sp., W. (W.) intermedium n. sp., Waagenophyllum (Liangshanophyllum) clisicolumellum n. sp., Ipciphyllum naoticum n. sp., I. floricolumellum n. sp., I. zandaense n. sp., and Gyanyimaphyllum crassiseptatum n. gen. n. sp. Ontogeny and intraspecific variation are given special attention when describing and discussing these taxa. Coral reefs, with Waagenophyllum as the major skeletal reef builder, occur in several horizons in the uppermost part of the section. The accompanying foraminifers indicate the rugose coral fauna is a late Permian Changhsingian age. Therefore, this is possibly one of the latest Permian rugose coral reefs in the world known up to now.

UUID: http://zoobank.org/b9e621cb-197d-4208-8267-14d62f382a1b

Two occurrences of Middle Ordovician opercula belonging to the gastropod Maclurites are described, one from the Taimyr Peninsula, Siberia, and one from the Kuskokwim Mountains, Alaska. The Taimyr opercula are the first to be described from Russia. Like other opercula of the genus, these thick specimens have a relatively massive prong on the interior to which the retractor muscle was attached. The Alaskan specimens preserve a secondary muscle attachment site. The described occurrences of Maclurites opercula are summarized.

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.

The discovery of a specimen of Rhaeboceras coloradoense Cobban, 1987, in the Baculites eliasi zone in east-central Montana is significant for three reasons: 1) it is the most geologically recent occurrence of Rhaeboceras; 2) it connects more closely than previous specimens the lineage between the genus Rhaeboceras Meek and Ponteixites Warren, its apparent smaller descendant; and 3) it significantly extends the geographical range of the species.

Echinoid fragments were reported by Zachos (1990) from a Weches Formation (Clairborne) outcrop on Hooker Creek in Burleson County, Texas. Enough fragments have been found at the latter locality to piece together a composite identifiable as a species of the spatangid genus Maretia, most likely M. arguta. This species has not previously been reported outside of Clarke County, Mississippi. A search of the stratigraphic collections of the Texas Memorial Museum in Austin, Texas, has uncovered several previously unidentified specimens of M. arguta from two Weches localities, at Kickapoo Shoals on the Trinity River in Houston County and at Nacogdoches in Nacogdoches County. In addition, spatangoid fragments, some of which are attributable to M. arguta, are common in collections from the Weches and Cook Mountain Formations.

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.

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.

New, distinctive, well-preserved and previously undescribed constituents of a Middle Ordovician (middle Darriwilian, Dw2) radiolarian assemblage from the Table Cove Formation in Newfoundland are described. Three-dimensional X-ray micro-computed tomography (μ-CT) facilitates detailed examination of key specimens revealing hitherto unknown details of the internal morphologies of key lower Paleozoic taxonomic groups, among which a lack of knowledge has previously impeded resolution of higher taxonomic rankings.

Twenty-seven archaeospiculid and entactinarian taxa are described and illustrated including six new species: Westernbrookia polygonata n. sp., Neopalaeospiculum piccadilliensis n. sp., Ramuspiculum laxum n. sp. Spongentactinia nazarovi n. sp., Aspiculum irregulare n. sp., and Nyfrieslandia ramosissima n. sp. The investigation extends the known ranges of the species: Pararcheoentactinia reedae Won and Iams, 2002; Sphaeroentactinia robusta Won and Iams, 2015; Varispiculum ectospiculatum Won and Iams, 2015; and Svalbardospiculum multifurcatum (Won, Iams, and Reed, 2005), together with the genus Echidnina to the mid-Darriwilian.

UUID: http://zoobank.org/74826b7b-bb86-45d5-ad23-e6e65e0706df.

A moderately diverse assemblage of brachiopods from the Latham Shale Lagerstätte (Cambrian Series 2, upper Stage 4) and the upper Cadiz Formation (Miaolingian, Wuliuan), California is described in detail for the first time. The fauna includes both linguliform and rhynchonelliform brachiopods—Hadrotreta primaea (Walcott, 1902), Paterina prospectensis (Walcott, 1884), Dictyonina pannula (White, 1874), and Mickwitzia occidens Walcott, 1908; and Nisusia fulleri Mount, 1981 and Wimanella highlandensis (Walcott, 1886), respectively—together with olenellid trilobites and hyolithids. The fauna differs from other Cambrian Konservat-Lagerstätten (notably Cambrian Series 2 Chengjiang and Guanshan Lagerstätten, eastern Yunnan) in that the brachiopod shell valves in many cases are still preserved with their original mineralization. Moreover, the excellently preserved shale-hosted valves even include cases with exquisite epithelial cell molds, otherwise only seen in acid-etched material from carbonate rocks. The pitted ornamentation in D. pannula closely resembles that described from Ordovician linguliforms. The unusual preservation of N. fulleri provides important clues for ancestral composition of the brachiopod shell. The two articulated rhynchonelliform species probably represent the oldest records of this group from the west Laurentia. The fauna could also represent the earliest onset of the transition from the Cambrian Evolutionary Fauna (CEF) to the Paleozoic Evolutionary Fauna (PEF).

Squat lobsters within Galatheoidea are very diverse with over 1,300 extant species that live in all marine ecosystems, but their fossil record, starting in the Middle Jurassic, consists of only ~200 species. Consequently, much remains to be learned about their biodiversity, phylogeny, and paleobiogeography. We describe five new species (Galatheites sforum n. sp., Kimmeridgian, Late Jurassic, Germany; Vasconilia zapotitlanensis n. sp., Barremian, Early Cretaceous, Mexico; Eomunidopsis texcalaensis n. sp., Barremian, Early Cretaceous, Mexico; Protomunida bennickei n. sp., Danian, Paleocene, Denmark; and Protomunida eurekantha n. sp., Danian, Paleocene, Denmark) and one new genus (Tethysgalathea n. gen., Ypresian, Eocene, Italy). We further reassign Munida cretacea (Albian, Early Cretaceous, Texas, USA) to Galathea?, return Eomunidopsis? cobbani (Campanian, Late Cretaceous, Colorado, USA) to its original genus, report on the second occurrence of Vetoplautus latimarginus Robins et al., 2013 (Tithonian, Late Jurassic, Czech Republic), and reinstate Palaeomunidopsis moutieri (middle Bathonian, Middle Jurassic, France) as the oldest galatheoid known to date. The five new species, all found in limestones containing corals, increase galatheoid diversity in the fossil record by 2.5%. Finally, the common yet hitherto unrecognized Protomunida eurekantha was discovered by making casts of external molds, revealing distinct spines on the posterior margin that are more difficult to see in internal molds and specimens with cuticle due to breakage. Collecting and studying the external molds for galatheoids and other fossil decapods could yield additional cryptic species.

UUID: http://zoobank.org/68a25381-65c6-4773-a4f2-71d9b0a25304

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.