Rare specimens of eldonioids recovered from the lower Cambrian (Series 2, Stage 4) Emu Bay Shale (EBS) Konservat-Lagerstätte represent the first record of the group for the Cambrian of East Gondwana. The disc-shaped body of the EBS taxon bears fine concentric corrugations on the dorsal surface and, ventrally, a series of internal lobes that have primary and secondary bifurcations, as well as a coiled sac. It appears to be most similar to Rotadiscus and Pararotadiscus of the Cambrian Chengjiang and Kaili biotas of South China, respectively. While the structure of the internal lobes would indicate that this occurrence in the EBS represents a new taxon within the Rotadiscidae, lack of detail regarding the precise number of internal lobes and the condition of the circumoral tentacles warrants a more conservative approach in leaving the genus and species under open nomenclature. The EBS specimens also host trace fossils, including the remains of a burrow, which are generally lacking in the body-fossil-bearing layers of the Konservat-Lagerstätte interval. These traces appear to have been made by small organisms and are similar to traces associated with the discs of Pararotadiscus guizhouensis Zhao and Zhu, 1994 from the Kaili Biota. The available taphonomic, paleoenvironmental, and ichnological evidence indicates that the EBS eldonioids are most likely vagrants that were transported or settled into the ‘preservational trap’ and subsequently exposed on the substrate for a brief period before burial, thereby allowing organisms to exploit their carcasses for nutrients or other purposes.

Early Devonian (Pragian-Emsian) rocks in the Xainza region of central Xizang (Tibet) yield a shallow-marine, carbonate-platform fauna of corals, brachiopods, dacryoconarids, nautiloids and conodonts, among which Tibetatrypa n. gen. is locally a prominent constituent. The fauna broadly resembles that of western Europe, the Altai-Sayan region, the Urals and western Qinlin province of China, but differs from the South China faunas. Tibetatrypa, related to the Silurian genus Nalivkinia, is the youngest and largest member of the subfamily Clintonellinae, and is the first Devonian brachiopod described from Tibet.

Jurassic–Cretaceous ammonites are particularly robust fossil tools in global stratigraphy and correlation. The successive evolution and extinction of these cephalopod mollusks was so rapid that many ammonite zones are no more than one million years in duration. A well-preserved ammonite specimen from the Fortissimo-1 core, Browse Basin, NW Australia is assignable to the widespread latest Jurassic dimorphic berriaselline genus, Blanfordiceras Cossmann, recorded previously from the Spiti area, Nepal, Tibet, Madagascar, Papua-New Guinea, Antarctica, and southern South America. This is the first report of ammonites of this age in the Australian region. The evolute shell of an estimated 90-100 mm diameter (when extrapolated) and pronounced ornamentation of variably bifurcating, curvilinear and flexuous ribs, intercalated with simple, non-bifurcating ribs, is consistent with Blanfordiceras wallichi (Gray, 1832), which has traditionally been restricted to the uppermost Tithonian Stage, ca. 146.5-145.5 Ma, but may well have survived into the earliest part of the Berriasian. The first recorded occurrence of this ammonite in Australia fills an anomalous absence in the paleobiogeographic distribution of Jurassic–Cretaceous boundary ammonites in the Indo-SW Pacific Subrealm with important implications for the calibration of offshore rocks and wells in Australia.

Uintasoricines are diminutive plesiadapiforms that are found in the latest Paleocene through middle Eocene, predominantly in North America. They are not a diverse group but individual species may be locally abundant and they are a persistent element of the plesiadapiform radiation in North America surviving over a span of approximately 16 million years. Recent field work in southern Wyoming at South Pass has led to the discovery of a new genus and species of uintasoricine. The new form is smaller in tooth dimensions compared to other known uintasoricines, being slightly smaller than Uintasorex montezumicus from California. Both the newly described taxon and U. montezumicus are among the smallest plesiadapiforms yet known with body weights estimated to be 20 to 25 g. The sediments of the Cathedral Bluffs Tongue of the Wasatch Formation at South Pass contain a unique upland fauna—the presence of a distinctive uintasoricine in this assemblage adds further evidence to support the notion that this upland environment was a biodiversity hotspot during the latest early Eocene.

Two previously known species of stromatoporoids are reported from Nevada: Stromatoporella perannulata, from the Bartine Member of the McColley Canyon Formation (middle Emsian); and Stictostroma moosense, from the Oxyoke Canyon Sandstone (uppermost Emsian). A new species, Syringodictyon nevadense n. sp., is described from the Coils Creek Member of the McColley Canyon Formation (upper Emsian). Stromatoporella perannulata also occurs in Emsian-age strata on Ellesmere Island, arctic Canada, and in strata of Emsian and/or Eifelian age in Ontario, New York, Ohio, and Kentucky. Outside Nevada, Syringodictyon is confined to the Emsian of Ellesmere Island, and Emsian/Eifelian of Ontario and New York. Stictostroma moosense is known from only the Emsian/Eifelian of Ontario.

It is concluded that the three Nevada specimens are Emsian in age. This implies that in other localities where two of the species, S. perannulata and S. moosense, occur in strata where the placement of the Emsian-Eifelian boundary is in question, it might be higher than previously thought. The presence of the two species, plus Syringodictyon, in both the Old World Realm (Nevada, arctic Canada) and the Eastern Americas Realm (Ontario, New York, Ohio, Kentucky), infers a selective marine connection between the two realms that was not available to other taxa. The breach in the inter-realm barrier most likely occurred as a shallow seaway across the Canadian Shield.

UUID: http://zoobank.org/e73023c6-88ca-4b4d-9b01-f74a75b99c43

The geologic record of the shallow-marine gastropod genus Pseudoperissolax Clark, 1918 is documented in detail for the first time in a region of the northeast Pacific extending from southwestern Washington to northern Baja California, Mexico. This genus, which has been erroneously equated with the nomen dubium Perrisolax Gabb, 1861, comprises a very small group of species whose supra-generic ranking has been inconsistent. Pseudoperissolax is placed here in family Muricidae Rafinesque, 1815 and subfamily Muricinae Rafinesque, 1815 based on the presence of varices, a club-shaped last whorl with noded carinae, and a long siphonal canal. The genus is represented in the northeast Pacific by the late Paleocene Pseudoperissolax tricarnatus (Weaver, 1905) and the late Paleocene to late Eocene Pseudoperissolax blakei (Conrad, 1855).

Pseudoperissolax was a warm-water gastropod that most likely originated during the Late Cretaceous (Maastrichtian) in Madagascar and also questionably spread during this time to southern New Zealand. Its certain geologic range is early Paleocene to earliest Oligocene, with occurrences in western Kamchatka, southern Japan, southwestern Washington, southwestern Oregon, southern California, northern Baja California, Mexico, southern Alabama, and Nuevo León, northeastern Mexico. Whether Pseudoperissolax migrated into the northeast Pacific from Kamchatka or from Alabama and Mexico cannot be determined with certainty. The decline and eventual extinction of the genus coincided with the global-cooling event at the end of the Eocene.

Ichthyerpeton bradleyae (Huxley in Wright and Huxley, 1866) is one of the seven tetrapods originally described by Huxley from the Jarrow Assemblage (Pennsylvanian, Langsettian Regional Substage equated with the Bashkirian International Stage) in south-eastern Ireland. The holotype, one of only two specimens considered to represent the taxon, consists of the postcranial skeleton, which has been highly compressed and has undergone extensive replacement of bone by carbonaceous material. The holotype is studied using microcomputed tomography, which reveals that the vertebral column has at least 25 diplospondylous vertebrae with cylindrical centra. Neural arches and a haemal arch are described for the first time. Neural arches in the caudal region are paired and neural spines only contact one another dorsally. The hemal arch is fused and wraps around the ventral margin of the centrum. A stout femur and tibia are described. The morphology of the femur is unique for early tetrapods, with fibular and tibial condyles of similar length and lacking an adductor crest. The morphology of the femur, and its length relative to the tibia, suggests that the holotype of I. bradleyae preserves an immature individual. The tibia is a flat bone characteristic of stem tetrapods. Phalanges from the right and left pes are present. Because the phalanges are disarticulated, a phalangeal count cannot be determined. Despite the new anatomical information, the systematic position of I. bradleyae is still difficult to establish; however, it does not belong within the colosteids, temnospondyls, or embolomeres, to which it has previously been assigned.

The apparatus of Vogelgnathus simplicatus (Rhodes, Austin, and Druce, 1969) is reconstructed from discrete elements from a sample of limited diversity from the Limerick Province (Ireland). The apparatus is typical of the order Ozarkodinida and the P1 element was previously placed within Gnathodus. Here we assign it to Vogelgnathus by applying a multielemental concept rather than using P1 element morphology. The holotype and paratypes are re-illustrated and the species distribution revised based on published data. Vogelgnathus simplicatus ranges from the late Tournaisian to the early Viséan (Mississippian, Carboniferous), with common occurrences relating to the growth of Waulsortian bank complexes in a high-stand sea-level along the southern and western margins of the Laurussian landmass (Belgium, the British Isles, the Republic of Ireland, and USA). Vogelgnathus simplicatus appears to represent the rootstock from which deep-water and shallow-water Viséan species of Vogelgnathus evolved in the Mississippian.

The Suwannee Limestone of Florida and Georgia, USA, is a carbonate paleoenvironment with a rich diversity of marine fossils. These record the presence of coral- and seagrass-bearing communities in the western Atlantic from the Eocene/Oligocene boundary to the mid Oligocene (33.9–28.1 Ma). From the Suwannee Limestone, we describe two new species of the cosmopolitan, diverse, and abundant coral genus Acropora (“staghorn corals”), Acropora suwanneensis new species and Acropora upchurchi new species, which predate all other described Acropora species from the Americas and Caribbean by at least 10 million years. Diminutive skeletal structure in both species is indicative of their living in protected calm-water habitats. At their time of occurrence, an Atlantic–Pacific connection was open through Central America. Both species belong to morphological lineages also present in the fossil record of the eastern Atlantic (Europe, or the western Tethys). These lineages no longer occur in the Atlantic Ocean, but they are extant in the Indo-Pacific region, with the closest modern relative of each new species occurring in the Pacific Ocean to central Indo-Pacific. Some species in the two morphological lineages have existed for up to 20+ million years. The new species may have played a part in perpetuating a cosmopolitan Tethyan fauna and expanding Acropora habitats in the western Atlantic, by which they likely also contributed to the renowned species and habitat diversity of Acropora in the modern Indo-Pacific.

UUID https://zoobank.org/40118623-8b82-4352-a065-b58da74a5c41

An assemblage of 34 chiton valves collected from rocks of the “Imperial” Formation sensu lato at Super Creek near Palm Springs, California, is described here. The sedimentary rocks exposed at Super Creek were deposited in the proto-Gulf of California during the Late Miocene. This chiton assemblage represents the first reported Miocene chitons from western North America. The chiton valves are classified as Callistochiton cf. C. elenensis, Chaetopleura cf. C. lanuginosa mixta, Calloplax roederi n. sp., Chiton solaris n. sp., Callistoplacidae sp. indet., and Chaetopleuridae sp. indet. Thick valves dominate the assemblage. The chiton fossils reflect the overall faunal pattern from the “Imperial” Formation s.l. of a strong similarity to taxa in the modern Gulf of California, with a Caribbean component as well. This assemblage fills a gap in the chiton fossil record and preserves details of the adaptive radiation of the Polyplacophora that occurred at the time in concert with the onset of an upwelling regime.

UUID: http://zoobank.org/9947bfc9-84a3-4358-bac7-e660b936b067

Trilobites from the upper Guzhangian of the southern Argentine Precordillera, preliminarily described by Carlos Rusconi in the 1950s, are revised herein. The specimens studied were collected from an allochthonous limestone block of La Cruz Olistoliths at 200 m northwest of Estancia San Isidro locality (San Isidro area, Mendoza). Taxa comprise Kormagnostus seclusus (Walcott, 1884), Cedaria prolifica Walcott, 1924, C. puelchana Rusconi, 1954, Tricrepicephalus texanus (Shumard, 1861), Meteoraspis metra (Walcott, 1890), Coosia conicephala (Rusconi, 1954) new combination, Coosella texana? Resser, 1942, Nasocephalus cf. N. nasutus Wilson, 1954, and Olenoides proa (Rusconi, 1954) new combination. The North American genera Meteoraspis Resser, 1935 and Nasocephalus Wilson, 1954 are reported confidently from South America for the first time. This assemblage is representative of the Cedaria prolifica Zone, which correlates with the lower Crepicephalus Zone of the traditional North American genus-based zonation. Most of the genera and species identified were previously described exclusively from Canada, the United States, and northwestern Mexico, a fact that provides new support to an allochthonous Laurentian origin of the Argentine Precordillera.

Conularina triangulata (Raymond, 1905), the genotype of Conularina Sinclair, 1942, is a rare, early Late Ordovician conulariid (Cnidaria, Scyphozoa; Van Iten et al., 2006) having three sides or faces instead of four (Sinclair, 1942, fig. 9; Van Iten, 1992, text-fig. 3E). Originally described from the Valcour Formation (early Sandbian; Dix et al., 2013) on Valcour Island, New York (Sinclair, 1942), C. triangulata has since been found in laterally equivalent strata of the upper Laval Formation (‘Upper Chazy’; Sinclair, 1942) in Laval, Québec, Canada (Sinclair, 1942). From this same unit and area, Sinclair (1942) erected three new, four-sided species of Conularina (C. irrasa, C. raymondi, and C. undosa), and he erected a single four-sided species (C. narrawayi) from the Ottawa Formation (now the Sandbian–Katian Ottawa Group; Dix et al., 2013) at Tétreauville (now Gatineau), Québec. Subsequently, Jerre (1994) reported the occurrence of two species of Conularina in the Upper Ordovician of Sweden. Jerre (1994) also proposed that Eoconularia? forensis Sinclair, 1946 from the Upper Ordovician Citadelle Formation (‘Quebec City’ Formation; Sinclair, 1946) in Québec City, Québec (Promontoire de Québec thrust sheet, Appalachian Humber Zone, Allochtonous Domain; Castonguay et al., 2002) is a species of Conularina.

Complete body fossils of salamanders are relatively rare, but provide critical information on the evolutionary roots of extant urodele clades. We describe new specimens of the fossil salamandrids Taricha oligocenica Van Frank, 1955, and Taricha lindoei Naylor, 1979, from the Oligocene Mehama and John Day formations of Oregon that illustrate aspects of skeletal morphology previously unseen in these taxa, and contribute to our understanding of population-level variation. Morphological analysis of these specimens supports the classification of T. oligocenica and T. lindoei as two different species, distinct from extant Taricha. Parsimony-based, heuristic analysis of phylogeny using 108 morphological characters for 40 taxa yields different results from a phylogenetic analysis that excludes four taxa known only via vertebrae. Our smaller analysis generally agrees with molecular phylogenies of the family Salamandridae, but with poorer resolution for molgin newts, especially between Taricha and Notophthalmus. The analysis including all taxa produced polytomies mostly related to complications from several fossil taxa. The presence or absence of dorsally expanded, sculptured neural spine tables on trunk vertebrae, an important character in past descriptions of fossil salamandrids, appears to be either homoplastic within the Salamandridae, or requires an expansion of characters or character states. Taricha oligocenica and T. lindoei are separate species of an at least 33 million-year-old clade, but their relationships with each other and extant North American salamandrids remain unclear with current levels of morphological data. Salamandrid research requires additional morphological data, particularly for the vertebrae and ribs, to better resolve salamandrid evolutionary history through morphological characters.

A diverse Permian crinoid fauna is reported from the Taiyuan Formation, Dajian Member (Asselian) at Anyang, northeastern Henan Province of the North China Craton. The specimens are well preserved, including articulated crowns and cups. The fauna contains representatives of each of the major Paleozoic crinoid clades: Cladida (including the Flexibilia), Disparida, and Camerata. Identified genera suggest a greater affinity with North American faunas than with Tethyan faunas. Four new species, Neoprotencrinus anyangensis, Ulocrinus qiaoi, Artichthyocrinus limani, and Synbathocrinus chenae, are proposed herein.

UUID: http://zoobank.org/D08DDDCD-485C-45CC-A014-C1CB58C26588

The diversity of mid-Cretaceous tyrannosauroids is poorly understood. We describe a partial tyrannosauroid femur from the Albian–Cenomanian Wayan Formation of eastern Idaho that helps to fill in an important spatiotemporal gap in the North American record of tyrannosaurs. This specimen, consisting of the proximal half of the bone, is morphologically similar to the femur of Moros intrepidus, a small-bodied tyrannosauroid from the Cenomanian Mussentuchit Member of the Cedar Mountain Formation of Utah, but not referable to this taxon. The Wayan femur lacks an autapomorphy diagnostic for Moros intrepidus, indicating the presence of a previously unrecognized tyrannosauroid taxon in the early Late Cretaceous of Laramidia. Histological results indicate that, at the time of death, this individual was at least five years old, skeletally immature, and undergoing growth at a moderate rate. The addition of this tyrannosauroid to the Wayan-Vaughn Assemblage provides additional evidence for the widespread distribution of various tyrannosauroid taxa in Laramidia during the early Late Cretaceous.

The terminal Ediacaran Period is signaled worldwide by the first appearance of skeletonizing tubular metazoan fossils, e.g., Cloudina Germs, 1972 and Sinotubulites Chen, Chen, and Qian, 1981. Although recent efforts have focused on evaluating the taxic composition and preservation of such assemblages from the southwestern United States, comparable forms reported in the 1980s from Mexico remain to be re-examined. Here, we reassess the latest Ediacaran skeletal materials from the La Ciénega Formation of the Caborca region in Sonora, Mexico, using a combination of analytical methods: optical microscopy of extracted fossils, thin-section petrography, scanning electron microscopy and energy dispersive X-ray spectroscopy, and X-ray tomographic microscopy. From our examination, we conclude that the La Ciénega hosts a polytaxic assemblage of latest Ediacaran tubular organisms that have been preserved through two taphonomic pathways: coarse silicification and calcareous recrystallization preserving finer details. Further, these fossils show signs that their shells might not have been inflexible or completely mineralized in vivo, and that they might also record tentatively interpreted predation traces in the form of drill holes or puncture marks. This work, along with ongoing efforts around the world, helps to provide a framework for biostratigraphic correlation and possible subdivision of the Ediacaran Period, and further shapes our view of metazoan evolution and ecology in the interval directly preceding the Cambrian explosion.

Mackenzie Gordon, Jr., 78 (Figure 1), was a geologist and paleontologist with the U.S. Geological Survey (USGS) for more than 40 years. Mac, as he was affectionately known, died of cardiac arrest at his home on 30 January 1992 after a very brief illness. He is survived by his wife Barbara Walker Gordon of Washington, D.C.