The Angosto de Lampazar, a classic locality for the study of lower Paleozoic successions in the Cordillera Oriental, NW Argentina, has yielded a late Cambrian relatively diverse, lingulate brachiopod fauna. Sandy lenses with calcareous cement from the uppermost levels of the Lampazar Formation have yielded abundant remains of articulate and phosphatic brachiopods. Among the latter, the new species Eurytreta harringtoni Mergl and Herrera, Lingulella? melonica Mergl and Herrera, Libecoviella lenticularis Mergl and Herrera, and Schizambon cardonalis Mergl and Herrera, as well as the new genus and species Saltaia lampazarensis Mergl and Herrera are formally introduced. Trilobites and conodonts from the same horizons characterize the Cordylodus proavus Zone, allowing a correlation with Stage 10 of the Furongian Series. Although the information on lingulate brachiopods from the C. proavus Zone is scarce across the world, the composition of the studied association displays a relationship with coeval and slightly younger faunas of Utah and Kazakhstan. The Argentine brachiopods, the first described from the late Cambrian Proto-Andean margin of Gondwana, are more closely related to temperate Laurentian faunas than to those from the high latitude North African margin of Gondwana.

A dorsal valve of an Upper Cambrian lingulate brachiopod exhibits a repair scar on the anterior lateral edge of its larval shell. This species is characterized by an abrupt change in ornamentation from larval to postlarval growth. Shell material secreted in the injured area after the damage occurred exhibits ornamentation that is characteristic of postlarval growth, although equivalent growth exhibits characteristics of the larval stage. A break in the edge of the shell is visible, and the growth lines of the larval and postlarval shell were distorted until the broken area was filled in. Damage to the surface of the shell is interpreted to have been caused by the same event. Modern lingulate brachiopod larvae are planktotrophic and are interpreted to have been so throughout their long geologic history. Therefore, an environmental cause of shell damage seems unlikely and the injuries are interpreted to have been caused by an unknown durophagous predator. This specimen offers evidence that lingulate brachiopod larvae were able to survive shell breakage and repair their shells.

Extant members of the neogastropod family Conidae (cone snails) are renowned for their often dazzling shell coloration patterns and venomous feeding habits. Many cone snail species have also been described from the fossil record, but to date have been little used to understand the evolutionary history of extant clades. The cone snail fauna of the Miocene Gatun Formation of Colón Province, Panama is especially important for understanding the temporal and biogeographic history of tropical American Conidae. Intensive, focused collecting from an exposure of the lower Gatun Formation (deposited ca. 11–10 Ma) resulted in the discovery of nearly 900 specimens of Conidae. Remarkably, many of these well-preserved specimens exhibit revealed coloration patterns when exposed to ultraviolet light. The fluorescing coloration patterns were used in conjunction with other features of shell morphology to differentiate species and, in most cases, evaluate their potential relationships to members of the extant tropical American fauna. Nine species are fully described from this locality, one of which is recognized as new: Conus (Stephanoconus) woodringi n. sp. At least one, and perhaps more, additional Conidae species are also present at the study locality. The diversity of this Conidae fauna is considered moderate relative to other recently analyzed tropical American fossil assemblages. The phylogenetic diversity of the assemblage, however, is noteworthy: six of the ten species can be confidently assigned to six different clades of extant Conidae, providing potentially useful calibration points for future phylogenetic studies.

http://zoobank.org/8fe00c31-8f3f-4514-85af-29068e468cd3

The family †Peipiaosteidae contains the genera †Peipiaosteus, †Stichopterus, †Spherosteus, †Yanosteus, and †Liaosteus, all from Late Jurassic to Early Cretaceous deposits of China, Russia, Kazakhstan, and Mongolia. Although the family has taxonomically expanded since it was first established for †P. pani Liu and Zhou, 1965, the amount of detailed comparative data for many of the taxa involved is lacking. In this paper, we describe the osteology of the monotypic genus †Yanosteus from the Yixian Formation (Early Cretaceous) of China largely on the basis of a newly prepared, well-preserved specimen. †Yanosteus is characterized by a series of infraorbital ossicles (a characteristic of the family), a broad, rounded palatopterygoid, a robust dentary, an extremely small opercle and a subopercle with distinctly long and rounded anterior process and a posteriorly scalloped margin, a broad and weakly forked caudal fin, an elongate dorsal fin with more than 160–178 fin rays (diagnostic for the genus), and a short but well-formed pectoral fin spine. We use the results of this study to discuss the characters of the †Peipiaosteioidei and the diversity of †peipiaosteioids.

Oryctocephalid trilobites are seldom abundant and often tectonically deformed, creating problems for robust species delimitation and compromising their utility in biostratigraphic and evolutionary studies. By studying more than 140 specimens recovered from the upper portion of the Combined Metals Member (Pioche Formation, Nevada; Cambrian Stage 4, Series 2), we exploit a rare opportunity to explore how morphological variation among oryctocephalid specimens is partitioned into intraspecific variation versus interspecific disparity. Qualitative and quantitative analyses reveal that two species are represented: Oryctocephalites palmeri Sundberg and McCollum, 1997 and Oryctocephalites sp. A, the latter known from a single cranidium stratigraphically below all occurrences of the former. In contrast to the conclusions of a previous study, there is no evidence of cranidial dimorphism in O. palmeri. However, that species exhibits considerable variation in cranidial shape and pygidial spine arrangement and number. Cranidial shape variation within O. palmeri is approximately one-half of the among-species disparity within the genus. Comparison of cranidial shape between noncompacted and compacted samples reveals that compaction causes significant change in mean shape and an increase in shape variation; such changes are interpretable in terms of observed fracture patterns. Nontaphonomic variation is partitioned into ontogenetic and nonallometric components. Those components share similar structure with each other and with interspecific disparity, suggesting that ontogenetic shape change might be an important source of variation available for selection. This highlights the importance of ontogenetic and taphonomic sources of variation with respect to species delimitation, morphospace occupation, and investigation of evolutionary patterns and processes.

A reassessment of the taxonomic relationships of North American gigantopterids is presented in light of an examination of large populations of specimens housed in the US National Museum of Natural History. Variations in venation and subtle aspects of leaf shape facilitate refined understanding of the relationships and diversity of the North American gigantopterid species leading to an improved understanding of the taxonomic and biogeographic relationships of this group, which are found most abundantly in western equatorial Pangea and Cathaysia. Current literature suggests that there are eight North American genera, however, this study has revealed a morphological overlap of several previously defined genera, leading to the conclusion that Gigantopteridium encompasses the species previously treated as Cathaysiopteris yochelsonii as well as a new species, Gigantopteridium utebaturianum. The transfer of C. yochelsonii to Gigantopteridium yochelsonii suggests that Cathaysiopteris may represent a genus endemic to Cathaysia, limiting the biogeographical connection between the regions to Zeilleropteris, Gigantopteridium, Euparyphoselis, and Gigantonoclea.

The calyx of a Paleozoic camerate crinoid is composed of a mosaic of large, polygonal plates. Ontogenetic size increase results from accretionary additions of calcite to thecal plates. When new calcite is added to the lateral edge of a plate, a new layer is also added over the external surface, obscuring the earlier growth stages of the plate. However, ontogenetic development can be studied by measurement of a growth series. This is illustrated by regression analysis of growth series of two Silurian species of the genus Eucalyptocrinites: E. crassus (Hall) and E. tuberculatus (Miller & Dyer). Growth of the principal plates is isometric; most growth parameters have a very similar mode of development in both species; only a few parameters show any specific difference. A table of correlation coefficients for 51 growth parameters demonstrates that the entire development of the calyx was highly coordinated throughout life, with coefficients almost always equal to or larger than 0.90. Integrated expansion of the cup plates provided a larger cavity for the viscera. The stem increased in diameter to support the increasingly larger theca, as did the diameter of the root system. Growth of the vaulted plates in the upper part of the theca provided a protective recess for the arms, which probably contributed to the evolutionary success of this animal on a widespread basis during the Silurian and Devonian.

Based upon growth studies, the following synonymies are suggested: E. constrictus Hall, E. ellipticus Miller, E. ovalis Hall, and E. subglobosus Miller are synonyms of E. crassus; E. clrodi Miller is a synonym of E. tuberculatus Miller & Dyer.

A new genus, a new subgenus, and five new species of pterioid bivalves are described from shallow-marine faunas in the middle lower to middle Eocene Bateque Formation in the vicinity of Laguna San Ignacio to about 105 km southward, Pacific coast of Baja California Sur, Mexico. Batequeus n. gen. is a medium-sized pectinid with equally convex valves, a short byssal notch, anterior auricles smaller than the posterior ones, the left valve with numerous very closely spaced radial riblets that show the imbricated growth lines very well, the right valve with about 30 low, flat-topped radial ribs that can be grooved, and intercalary ribs on both valves. It is only known from its type species, Batequeus mezquitalensis n. sp., which is from the middle Eocene part of the Bateque Formation. Spondylus batequensis n. sp., a very spinose species, is from the middle lower Eocene part of the Bateque Formation and is only the second reported Spondylus from the lower Eocene of the west coast of North America. Pycnodonte (Phygraea) pacifica n. sp., a species characterized by a radial sulcus that originates in the umbo area, occurs in both the middle lower and middle Eocene parts of the Bateque Formation. Phygraea has not been reported previously from the west coast of North America. Pycnodonte (Pegma) n. subgen. has a plicate left valve with a large attachment area (that can cover the entire valve) and a right valve that usually has an inflated smooth central area surrounded by plicate margins. It is only known from its type species, Pycnodonte (Pegma) bajaensis n. sp., which occurs in both the middle lower and middle Eocene parts of the Bateque Formation. Cubitostrea mezquitalensis n. sp., a strongly ornamented species, is from the middle Eocene part of the Bateque Formation and is the first occurrence of this genus from the west coast of North America.

Three of Kitchin's (1903) trigoniid species, Trigonia trapeziformis, T. spissicostata, and T. cardiniiformis, have been frequently examined taxonomically, but their phylogenetic relationships remain uncertain. Taxonomic designations have ranged from grouping them within a single subgenus to separating them into different subfamilies. Principal factors affecting the previous studies include: excessive weighing of certain features from a typological perspective; phylogenetic relationships established on the basis of plesiomorphic characters which are applicable even at the family level. Although they are endemic to Kutch, India, species' ancestries were rarely sought from the regional taxa, a situation exacerbated by inadequate stratigraphic information. This study reveals that all the three species are both geographically and stratigraphically distinct, and their distribution is linked to major regression events. Since the latest Jurassic, the Kutch Basin experienced shallowing. The unstable environment triggered a substantial diversification of new forms. The present species are close morphologically to some endemic species of different genera. Detailed morphologic, morphometric, and cladistic analyses reveal affinities between ‘Eselaevitrigonia’ trapeziformis and Indotrigonia smeei, as well as ‘E.’ spissicostata and Opisthotrigonia retrorsa. It is believed that E. cardiniiformis evolved from ‘E.’ spissicostata. In each case, speciation took place in a very shallow, high-energy, nearshore environment and proceeded through various heterochronic processes. The pattern is consistent with a punctuated model of evolution. Gondwana fragmentation and rise of eustatic sea level during the Aptian opened up the central Indian oceanic corridor, prompting the spread of ‘Eselaevitrigonia’ to the Austral Province.

Epistreptophyllum cornutiformis Gregory, 1900, is the name assigned to a Middle Jurassic population of scleractinian corals from Kachchh, western India. Measurements of ten variables from 84 specimens of this population have been statistically examined by means of univariate and multivariate analyses. A wide range of variation in corallum shape, septal perforation, lateral septal surface ornamentation, nature of the endotheca, and that of the columella is observed. The great majority of specimens are solitary. The wide range of gradational variation observed in this population corresponds to and includes the morphological characters described for various scleractinian genera such as Protethmos Gregory, Metethmos Gregory, Frechia Gregory, and Epistreptophyllum Milaschewitsch. The assignment of these genera to this later senior synonym genus is supported by the description of a well-preserved topotype from Nattheim. The ornamentation of the septa in Epistreptophyllum is detailed and distances it from typical pennular corals.

A new genus, Novoameura, is erected with the type species Anisopyge mckeei Cisne. Delaria macclintocki Cisne from the Kaibab Formation of Arizona is herein regarded as a junior synonym of Delaria sevilloidia (Chamberlain), which was originally described from the Phosphoria Formation of Wyoming. The Leonardian (Permian) San Andres Formation of the Sacramento Mountains, central New Mexico, contains trilobite species known both from the Kaibab Formation of Arizona and the Phosphoria Formation of Wyoming, but lacks trilobite species known from the nearby Permian of West Texas.

New phylogenies of endemic Pectinidae of the Galápagos Islands allow their endemic status to be assessed relevant to the relict theory of insular endemism. Nodipecten magnificus and Leopecten isabelensis n. sp. are neoendemic species that evolved in the Pliocene from ancestors in the tropical eastern Pacific and more remote ancestors in the Tertiary Caribbean Province before closure of transisthmian seaways. Spathochlamys vestalis, an eastern Pacific species whose incipiently neoendemic Galápagos representatives have diverged only slightly from the mainland stock, is related to an extant, broadly distributed western Atlantic sister species, S. benedicti, which has an ancestry traceable back to the Miocene in the Tertiary Caribbean Province. Euvola galapagensis is a paleoendemic whose ancestral lineage is extinct on mainland coasts. Veprichlamys incantata is a paleoendemic with an exclusively Pacific history, with its probable immediate ancestor occurring in the Pliocene of Ecuador and its more remote Miocene ancestors in the cooler waters of the southeastern Pacific. The high frequency of endemism and the evidence that originations are Pliocene or later are consistent with the high rates of morphological evolution attained by the Pectinidae relative to many other bivalves.

New species described are L. isabelensis of the Galápagos Islands and L. cocosensis of Cocos Island. Leopecten is shown to be restricted to the Americas and to differ morphologically from Flabellipecten, an extinct Neogene European genus that is phylogenetically not closely related. Based on a new phylogeny, the genus Lyropecten is extinct, and living representatives of the Lyropecten-Nodipecten clade are all in the genus Nodipecten.

Ten species of brachyuran decapod crustaceans, including four new species, Matutites miltonorum, Pororaria? granulosa, Eocarpilius blowi, and Glyphithyreus sturgeoni, are described from the Eocene Castle Hayne Formation in North Carolina. In addition, claw fragments suggest the presence of an additional four species. Analysis of the fauna within the formation, coupled with data from the enclosing rocks, suggests an environment of deposition in subtropical, clear water at shallow shelf depths. Wave and current energy were variable. Although no corpses were recognized and all the taxa were represented either by claw fragments or isolated carapaces, little abrasion or breakage was observed, which suggests that the material was deposited near the living site of the organisms. Many of the decapod taxa are congeneric with contemporaneous forms from Italy and with Miocene species in Hungary. Paleoceanographic modeling, using the Parallel Ocean Climate Model (POCM), forced by the GENESIS atmospheric circulation model, produces conditions of temperature, salinity, and ocean circulation that corroborate conclusions drawn from analysis of the Castle Hayne sediments and fauna and, additionally, yields similar conditions for the northern margin of the Tethyan region in the Mediterranean basin. Ocean circulation patterns demonstrate the feasibility of dispersal of subtropical organisms from the Mediterranean part of the Tethys across the Atlantic Ocean to the North American coastline.

Laminae of genera considered in this revision are sheets of planar, compact tissue (order Clathrodictyida) or a network formed by arms (colliculi) emerging from pillars (order Actinostromatida). Pillars, confined to a single interlaminar space, are simple rods, branch upwards, or have complex cross sections. The scope of Anostylostroma is limited to species with complexly upwardly branching pillars and simple planar laminae. Species with predominantly y- or v-shaped pillars are removed to Schistodictyon. Simplexodictyon is limited to species with double laminae formerly referred to Diplostroma. A new genus, Petrostroma (type species: Simplexodictyon simplex Nestor), is proposed for species with simple, planar laminae and rodlike pillars. The scope of Atelodictyon is restricted to species with planar, simple laminae resembling the type species and many species with laminae formed of colliculi previously placed in this genus are assigned to Aculatostroma. Other genera discussed include: Crumplestroma and Coenellostroma (both synonyms of Aculatostroma), Pseudoactinodictyon, Stelodictyon, Clathrodictyon, and Nexililamina and Coenostelodictyon (both synonyms of Schistodictyon).

The Cenomanian ammonites of the Helvetic Domain (French-Swiss Western Alps) are revised and illustrated for the first time since the middle of the Nineteenth Century. The faunas occur in remarkable condensed hemipelagic glauconite-rich biomicrites that also contain planktic foraminifera and small stromatolites. Thirty-three ammonite species referred to 15 genera are described; the assemblage extends from the lower part of the Lower Cenomanian Mantelliceras mantelli Zone (Neostlingoceras carcitanense Subzone) to the lower part of the Middle Cenomanian Acanthoceras rhotomagense Zone (Turrilites costatus Subzone). The assemblage comprises 57 percent trachyostracous forms, 41 percent heteromorphs of the standard N.W. European sequence, and 2 percent leiostracous forms, which inhabited an external shelf biome. The biogeographic affinity of this fauna is essentially cosmopolitan (69 percent), but 31 percent of the specimens belong to the European Boreal biota, with no Tethyan taxa.

Hydrothermal vents and methane seeps sustain unique ecosystems with a highly adapted fauna that largely thrives on chemotrophic endosymbionts. This large biomass attracts not only predators but also parasitic taxa like the recently reported oophagous bivalve Acesta bullisis Vokes, 1963 that lives permanently attached to a vestimentiferan tube worm (Järnegren et al., 2005). Here I report large brachiopods of the Early Cretaceous seep-restricted genus Peregrinella Oehlert, in Fischer, 1887 that were infested by polychaete tubes inside their shells during their lifetime.

A single large colony (20 cm) of Rhombopora blakei n. sp. from the Hook Head Formation of Ireland (Tournaisian Stage, Mississippian) permits an analysis of within-colony variation associated with environmental change at a calendar scale (days to decades). Morphometric data for three external characters—apertures spacing along a branch and diagonal to a branch as well as lateral zooecial spacing—were collected as growth series (16–30 generations) from 13 segments within the colony. ANOVA, post-hoc means testing and graphical analysis of standardized data revealed nearest neighbor effects at the zooecial level and non-random distribution of variances across the colony. Parametric tests for sequential nonrandomness revealed cyclic variation through growth transects at three levels (23.3, 9.4 and 5.3 generations). Comparisons to growth rates of modern bryozoans suggests that the longer-term cycles are annual and that the shortest cycles may be related to lunar tidal cycles. The exceptional size and preservation of this single specimen, which is a new species of rhabdomesine Bryozoa, reinforces the importance of collecting individual morphological measurements from randomly selected and widely spaced parts of a colony for taxonomic, evolutionary and ecological applications.

Sloths were among the most diverse groups of land vertebrates that inhabited the Greater Antilles until their extinction in the middle-late Holocene following the arrival of humans to the islands. Although the fossil record of the group is well known from Quaternary deposits in Cuba, Hispaniola, and Puerto Rico, remains from older units are scarce, limiting our understanding of their evolution and biogeographic history. Here we report the oldest known fossil ground sloth from Hispaniola, represented by an unassociated partial tibia and scapula that are recognized as a single taxon from the late Miocene-early Pliocene of the Dominican Republic. The combination of characters observed on the tibia suggests a close relationship with Megalocnus, otherwise only known from the Pleistocene–Holocene of Cuba. These fossils fill a temporal gap between those previously known from the early Miocene of Cuba and those from Pleistocene–Holocene deposits in the region and provide additional support for a continuous presence of the group in the Greater Antilles since the Oligocene.

The Scotty Wash Formation on the Nevada Test Site (NTS), southern Nye County, Nevada has produced the first North American representatives of the globally significant index ammonoids Homoceras s.s. and Isohomoceras s.s. and contains the only ammonoid succession across an uninterrupted mid-Carboniferous boundary sequence known in North America.

Four ammonoid assemblages can be recognized at NTS that are homotaxial with the reference successions for the middle and upper Arnsbergian (E2) and Chokierian (H1) Stages, Namurian Series, in western Europe, and their equivalents worldwide. The upper Mississippian (Chesterian) portions of the NTS sections yield assemblages referable to a Eumorphoceras girtyi Ammonoid Biozone, representing the middle Arnsbergian Stage (E2b), followed by a Delepinoceras thalassoide Ammonoid Biozone, equivalent to the upper Arnsbergian Stage (E2c). The latter ammonoid biozone also occurs in the Imo and Rhoda Creek Formations of Arkansas and Oklahoma, requiring reassignment of those formations to the upper Arnsbergian Stage (E2c). The appearance of the Isohomoceras subglobosum Ammonoid Biozone marks the base of the Chokierian Stage (H1a) at NTS. The zonal name-bearer continues into lower Pennsylvanian (Morrowan) strata, where it joins the Homoceras coronatum coronatum Ammonoid Biozone assemblage in an interval equivalent to the upper Chokerian Series (H1b). A pronounced unconformity at NTS separates the Scotty Wash Formation from the overlying Tippipah Limestone, which contains a fifth ammonoid assemblage characterized by Cancelloceras cf. C. elegans that is equivalent to the Yeadonian Stage (G1), Namurian Series, of western Europe.

The conodont succession recovered from the ammonoid-bearing sections at NTS allows refined correlation of the Arnsbergian and Chokierian Stages with the Mid-Carboniferous Global Stratotype Section and Point (GSSP) at nearby Arrow Canyon, Nevada, and the North American midcontinent. The Lower Rhachistognathus muricatus Conodont Biozone of western North America is equivalent to the upper Arnsbergian Stage (E2c), and must include the upper portion of the Adetognathus unicornis Conodont Biozone as recognized in the midcontinent. The Upper R. muricatus Conodont Biozone is equivalent to that portion of the Chokierian Stage (H1a) below the appearance of Declinognathodus noduliferus, marking the mid-Carboniferous boundary horizon, including some of the R. primus Conodont Biozone as used in the North American midcontinent. The intercontinental mid-Carboniferous boundary, drawn at the appearance of D. noduliferus, does not correspond to the Arnsbergian-Chokierian Stage boundary (E2c-H1a) that is defined by the appearance of Isohomoceras subglobosum. A significant break occurs in the Arrow Canyon GSSP less than 4 m above the position of the mid-Carboniferous boundary, where Chokerian strata (H1) are probably succeeded by Kinderscoutian strata (R1). Higher at Arrow Canyon, the position of the Scotty Wash-Tippipah unconformity juxtaposes Kinderscoutian and Yeadonian (G1) strata and the entire upper Namurian Series is limited to no more than 54 m.

Comparison of Eurasian and North American ammonoid assemblage compositions suggests that at least intermittent faunal interchange persisted between the two regions until at least the close of the Chokierian.

Definition of the Mississippian-Pennsylvanian boundary, which has never been defined faunally in either type area, to correspond to the intercontinental mid-Carboniferous boundary would be compatible with relationships known in the Chesterian and Morrowan type areas.

Taxonomic treatment of the Chokierian ammonoid assemblage from Syncline Ridge, NTS provided herein includes Proshumardites karpinskii Rauser-Tschernoussova, 1928; Eosyngastrioceras inexpectans Titus, 2000; Somoholites cf. S. merriami (Miller and Furnish, 1940b); Euroceras ellipsoidale Ruzhencev and Bogoslovskaya, 1971a; Isohomoceras subglobosum (Bisat, 1924); Homoceras diadema (Beyrich, 1837); H. coronatum coronatum (Haug, 1898); and H. leedomi new species.