The genus and species Johnognathus huddlei Mashkova, 1977, is synonymized with Distomodus staurognathoides (Walliser, 1964) on the basis of common occurrence, similar morphology, and the discovery of a complete S element of D. staurognathoides with a posterior process developed into a platform that is identical in morphology to specimens referred to J. huddlei.

The Silurian and Devonian plant fossil record is the basis for our understanding of the early evolution of land plants, yet our appreciation of early global phytogeographic evolution has been constrained by the focus of most studies on deposits from Europe, North America, and, more recently, South China. Devonian plants have been recorded rarely from northeastern China, and among previous records, few plants have been illustrated and formally described. In this article, megafossil plants representing a Late Devonian-aged (probably Famennian) flora are described from a locality at northern Sonid Zuoqi, Inner Mongolia, NE China. The flora includes Melvillipteris sonidia new species, Archaeopteris sp., and fragments of some other plants. The new plant shows main axes and two orders of lateral branches. The first-order branches of this plant show a typical zigzag appearance and are borne in pairs on main axes. Second-order branches are straight or slightly flexed, and are borne helically or alternately on first-order branches. Sterile ultimate appendages and fertile structures of M. sonidia n. sp. are borne alternately on second-order branches. An associated palynological assemblage, as well as U-Pb ages of detrital zircon grains from adjacent horizons, are also reported, indicating a Late Devonian age in accord with the megafossil plants. The present study contributes to our appreciation of the Devonian floristic diversity of the Xing'an Block, and, through our review of the record of early vascular plants from NE China, more broadly to the understanding of the mid-latitude vegetation of the Northern Hemisphere during the Late Devonian.

Specimens of the Late Mississippian productoid genera Inflatia and Keokukia from northeastern Oklahoma and northwestern Arkansas, collected from the Boone and “Moorefield” Formations, Hindsville Limestone, and Fayetteville Shale, display morphologic similarities and differences that delineate species and determine their biostratigraphic ranges. Generic assignments are based primarily on internal characters. Systematic descriptions include seven species of Inflatia Muir-Wood and Cooper: Productus inflatus McChesney (the type species), P. cherokeensis Drake, P. clydensis Girty (figured herein for the first time and for which a lectotype is designated), four new species of Inflatia (I. cooperi, I. gracilis, I. pusilla, and I.? succincta), and one species of Keokukia (the type species for the genus, K. sulcata Carter). Also proposed and described is a new genus, Adairia, with its type species Productus (Marginifera) adairensis Drake. All these species of Inflatia, Keokukia, and Adairia have biostratigraphically restricted ranges within the Meramecian and Chesterian sequence in the Ozark region.

The genus Merychippus was erected by Leidy (1857), who named as the type species Merychippus insignis. The type specimen of M. insignis is an immature and incomplete maxilla containing a broken dp2 and a dp3. The type comes from the Bijou Hills of South Dakota, probably from the Barstovian (middle Miocene) Fort Randall Formation of South Bijou Hill in Charles Mix County (Skinner and Taylor, 1967), but possibly from the overlying undifferentiated Ogallala Formation, or possibly from North Bijou Hill in Brule County. Despite this enigmatic type, the species M. insignis has frequently been identified in the fossil record, and the genus Merychippus has grown to include all mesodont horses (Stirton, 1940). Conceptually, the taxon Merychippus is considered a horizontal grade rather than a vertical clade (Simpson, 1945, p. 18). As a horizontal concept, the genus Merychippus derived importance as the ancestral group for the many Mio-Pliocene lineages of hypsodont horses. Today, as horse classification is remodeled along cladistic lines, the taxon Merychippus derives importance from its early naming. Several distinctive horse clades extend upward from a middle Miocene radiation (Stirton, 1940; Quinn, 1955). If M. insignis can be placed within one of these clades, then it is likely that the clade will bear the generic nomen Merychippus because of the antiquity of the name.

Bocchino (1964) described and figured a new genus and species, Propygidium primaevus, and assigned it to the siluriform family Trichomycteridae (=Pygidiidae). After examination of the holotype, the only referred specimen, the authors conclude that it does not correspond to a catfish, but to an acanthopterygian. Since it was considered the only fossil record of trichomycteridae, and having been used to support speculations on the “center of origin” of this Neotropical family (see Ringuelet, 1975), it is appropriate to correct the former assignment.

Permian colonial corals from Artinskian to Kungurian strata in the Conglomerate Mesa area, Inyo Mountains, east-central California, include five new species, one of which is assigned to a new genus. The new taxa are: Malpaisia maceyi n. gen. and n. sp., Pararachnastraea bellula n. sp., P. delicata n. sp., P. owensensis n. sp., and Cordillerastraea inyoensis n. sp. These species, several of which compare most closely with other Artinskian and Kungurian species from eastern Nevada and northern Mexico, represent three distinct stocks that differentiated on an isolated submarine uplift offshore from the main part of the Cordilleran carbonate shelf.

Girty (1910) described Patellostium laevigatum from the Fayetteville Shale (Mississippian, Chesterian) of Arkansas but did not provide illustrations. Yochelson (1969) redescribed and illustrated the type material, placing the species in the genus Patellilabia Knight, 1945.

Spirodentalium Walcott, 1890, was originally described as a scaphopod. A reinterpretation of the type lot suggests that its overall shape is that of an open-coiled gastropod. If so, this is probably the earliest known open-coiled form and it is sinistral in coiling direction.

Among hyoliths from the Givetian Kersadiou Formation in northwestern France one form is assigned to Hyolithes triliratus Hall, 1879, which is used as the basis for Brittanella new genus. The occurrence of this species in France supports affinity for fauna in that region to the Eastern Americas Realm. Other hyoliths from this unit include one species of Hyolithes Eichwald, which is left in open nomenclature, and one conch and one platyclaviculate operculum that cannot be identified to genus. The occurrence of these fossils in concretions in an oxygen-stressed dark gray shale supports the notion that this environment served as a refuge for taxa that were less efficient competitors with other normal marine benthos in the Devonian.

The Cambrian (Jiangshanian, Sunwaptan) Honey Creek Formation in the Wichita Mountains region of Oklahoma yielded a new fauna dominated by Monocheilus Resser, 1937 (senior synonym of Stigmacephalus Resser, 1937) in association with Ptychaspis Hall, 1863. It occupies the same stratigraphic position as similar faunas in the Upper Mississippi Valley and Alberta, lying a little above an interval characterized by species of Taenicephalus Ulrich and Resser in Walcott, 1924 and Orygmaspis Resser, 1937. Revision of Ptychaspis bullasa Lochman and Hu, 1959 from type material from Idaho and sclerites attributed to the species from Texas reveals a plexus of pseudocryptic species that share tuberculate sculpture on the cranidium. New species are Monocheilus reginae, Monocheilus richardi, Ptychaspis occulta, and Ptychaspis matuszaki.

UUID: www.zoobank.org/c2771c63-db4b-434a-ae58-3e3fda19ecb0

A new helminthomorph millipede, Sinosoma luopingense new genus new species, from the Triassic Luoping biota of China, has 39 body segments, metazonites with lateral swellings that bear a pair of posterolateral pits (?insertion pits for spine bases), and sternites that are unfused to the pleurotergites. This millipede shares a number of characters with nematophoran diplopods, but lacks the prominent dorsal suture characteristic of that order. Other “millipede” material from the biota is more problematic. Millipedes are a rare part of the Luoping biota, which is composed mainly of marine and near-shore organisms. Occurrences of fossil millipedes are exceedingly rare in Triassic rocks worldwide, comprising specimens from Europe, Asia, and Africa, and consisting of juliform millipedes and millipedes that are either nematophorans or forms very similar to nematophorans.

Karlsorus n. gen. is proposed in this study as a large, smooth-shelled pentameride brachiopod of the family Pentameridae, based on Pentamerus gothlandicus Lebedev, 1892, from the Wenlock (Silurian) Slite beds of Gotland, Sweden. This species is transferred from Pentamerus to the new genus because of the combination of a Pentamerus-like shell shape and the development of a brachiophorium through fusion of the outer hinge plates in the middle portion, like a dorso-ventrally inversed cruralium. The first appearance of brachiophorium in pentamerids is in the late Wenlock, known also in Brooksina, Pentamerifera, and other related pentamerid genera, marking a significant stage in morphological transformation of dorsal internal structures, as part of the Silurian pentameride diversification in both level-bottom and reefal depositional environments.

Ptychites is among the most widely distributed ammonoid genera of the Triassic and is namesake of a family and superfamily. However, representatives of the genus mostly show low-level phenotypic disparity. Furthermore, a large number of taxa are based on only a few poorly preserved specimens, creating challenges to determine ptychitid taxonomy. Consequently, a novel approach is needed to improve ptychitid diversity studies. Here, we investigate Ptychites spp. from the middle and late Anisian of Nevada. The species recorded include Ptychites embreei n. sp., which is distinguished by an average conch diameter that is much smaller and shows a more evolute coiling than most of its relatives. The new species ranges from the Gymnotoceras mimetus to the Gymnotoceras rotelliformis zones, which makes it the longest-ranging species of the genus. For the first time, the ontogenetic development of Ptychites was obtained from cross sections where possible. Cross-sectioning highlights unique ontogenetic trajectories in ptychitids. This demonstrates that, despite showing little phenotypic disparity, Ptychites was highly ontogenetically differentiated, and thus the high taxonomic diversity at the species level is justified for the species investigated.

UUID: http://zoobank.org/5abe2487-8a00-4b48-adc7-ec7db7a097f7

The western Mongolian Lake Zone was a Neoproterozoic to early Paleozoic volcanic arc where tuffs, lavas, fossiliferous siliciclastics, and carbonates accumulated during the early Cambrian. An uppermost Cambrian Series 2 (upper Stage 4) trilobite assemblage is described here from the Burgasutay Formation representing a continuous lower Cambrian succession at the Seer Ridge of the Great Lake Depression. The new assemblage is dominated by dorypygids and consists of 13 trilobite genera belonging to nine families including Catinouyia heyunensis new species. These fossils comprise the youngest and richest lower Cambrian trilobite assemblage in Mongolia. The composition of the Lake Zone fauna suggests its biogeographic affinity with the Siberian Platform and Altay-Sayan Foldbelt, but the presence of inouyiids also implies a connection of this region with East Gondwana.

UUID: http://zoobank.org/fb0ebe23-144f-46ed-9543-7df9eea85fbc

A series of well-preserved specimens of the little-known Palaeogene species Biselenaria placentula (Reuss, 1867) warrant the designation of a new family of free-living cheilostome bryozoans, Biselenariidae n. fam. In contrast to the structural organization of all other free-living, lunulitiform cheilostomes, all zooids are enclosed almost completely by cuticular, exterior walls. Yet, like other lunulitiforms, the colony must be regarded as a highly integrated functional unit, as revealed through the unique, highly complex interior architecture. In creating the new monotypic family, the type species Biselenaria placentula is described in detail, while the ambiguous taxonomic status of the only other taxon, B. offa Gregory, 1893, is discussed.

UUID: http://zoobank.org/6ad8a795-c45e-4619-b2bb-46916585fbd9

The description of a specimen of Aturia coxi from the uppermost Miocene of central Japan provides additional data on this poorly known Neogene species. Aturia coxi Miller is the youngest representative of this nautiloid genus, which is known from the middle to upper Miocene formations of the Indo-Western Pacific and became extinct at the end of Miocene. In addition to the presence of Aturia coxi, the abundance of tropical and subtropical benthic molluscs indicates that tropical molluscan faunas invaded mid-latitude waters around Japan in the latest Miocene. The extinction of Aturia and other Miocene molluscan genera marks the end of the Miocene Epoch.

Tang et al. (2019) described new specimens of carbonaceous compression fossils from the early Cambrian Hetang Formation in South China, for which they established the new taxon Cambrowania ovata Tang and Xiao in Tang et al., 2019. Tang et al. (2019) interpreted these fossils as the remains of metazoans, representing either the carapaces of bivalve arthropods, or early life-cycle stages of sponges. We contest the animal affinity of these fossils; instead, we propose that the specimens described as Cambrowania ovata are actually large Leiosphaeridia—in other words, collapsed hollow organic spheroidal acritarchs. The features described by Tang et al. (2019) all fall into the morphology of carbonaceous compressions of Leiosphaeridia with pyritized/baritized folds and compaction wrinkles. Such Leiosphaeridia are a common component of Cambrian (and older) siliciclastic deposits, and frequently exhibit such a pattern of pyritization, baritization, and encrustation with other diagenetic minerals.

Silicified and well-preserved specimens of the new orchocladine anthaspidellid genus and species, Virgaspongia ichnata, the rhizomorine haplistiid, Haplistion sphaericum Finks, 1960, and various root tufts, and the new hexactinellid species Steioderma hadra are reported from the Brentwood Member of the Morrowan Bloyd Formation from the Sulphur City quadrangle, in the Ozark Mountains of northwestern Arkansas. Virgaspongia is a subcylindrical branched or unbranched sponge that lacks a spongocoel and has a dendroclone-based skeleton in which trabs diverge upward and outward from an axial region. It is abundant here but is one of only a few anthaspidellid genera known from the Pennsylvanian. This is the first record of Haplistion from Pennsylvanian rocks of Arkansas, although the genus is widespread in upper Paleozoic rocks. The new hexactinellid species, Stioderma hadra, also documents the first occurrence of that genus from Arkansas and in Morrowan rocks. Only fragments were recovered but the swollen grotesque spicules, of several sizes, that make the fused dermal layer and outer sponge wall are distinctive, particularly where combined with an inner layer(?) or root tuft of monaxons of various sizes. Two different root tufts and one demosponge wall fragment(?) also occur in the collection.

The Pratt Ferry beds are a three meter thick bioclastic carbonate unit containing the Pygodus serrus–P. anserinus conodont zone boundary and lying just below the Nemagraptus gracilis graptolite zone at a single locality in Alabama. Telephina Marek at Pratt Ferry and other eastern North American localities is represented by at least six species. These are judged widespread and in part conspecific with Scandinavian or Asian forms of similar age. Most of the fifteen Appalachian telephinid species proposed by Ulrich (1930) are reviewed and some synonymized. Bevanopsis Cooper is present, extending its stratigraphic range via B. buttsi (Cooper). The original description of Ceraurinella buttsi Cooper is augmented. Other recorded but poorly represented genera include Ampyxina, Arthrorhachis, Calyptaulax, Hibbertia, Lonchodomas, Mesotaphraspis, Porterfieldia, and Sphaerexochus. The entire faunule represents a mixture of ‘inshore’ and ‘offshore’ or planktonic faunal elements rarely seen elsewhere in the latest Middle Ordovician (Darriwilian) of eastern North America.