Although the well-known Upper Jurassic Morrison Formation has yielded abundant fossil plants for nearly a century, relatively little is known about fossil fungi and their ecological relationships to the Morrison flora. The first mention of fungal decay in fossil wood was briefly made over three decades ago, and since then, a few more reports of fungal decay associated with Morrison plants have been published. However, up to now, detailed data on the fossil fungi themselves have not been given from the Morrison Formation. Here we describe in detail well-preserved fossil mycelia in a silicified log of Xenoxylon utahense Xie et Gee, 2021 from the Upper Jurassic Morrison Formation at Miners Draw, Blue Mountain, near Vernal in northeastern Utah, USA. The fungal hyphae are variable in form, ranging from straight to slightly curved to highly coiled to tubular; they measure ~1.53 μm in diameter and possess clamp connections, septa, and occasional bifurcations. The occurrence of clamp connections typical of living Basidiomycota indicates a taxonomic affinity to this division of fungi. On the basis of the patterns of wood decay in the Xenoxylon log, the fossil fungi are interpreted here as pertaining to saprotrophic, white-rot wood fungi. These fossil mycelia represent a new record of ancient Basidiomycota from the Upper Jurassic Morrison Formation and provide further evidence for plant–fungus interactions in Jurassic terrestrial ecosystems.

Upper Carboniferous and Lower Permian shallow marine rocks in the Pequop Mountains of northeastern Nevada contain an abundance of fossils, especially fusulinids and fasciculate corals. As the composite stratigraphic section in this area represents the most nearly complete sequence of this type of corals anywhere in the Cordilleran miogeocline, this study was undertaken to document their occurrence sequentially. This information should be useful for comparison with other sections in the miogeocline containing similar corals.

Only one species of Durhamina is present in the Gzhelian rocks. Durhamina, Heintzella, and Paraheritschioides occur in the Asselian rocks, and all of these genera plus Wilsonastraea are present in the Sakmarian part of the section. Corals in the Artinskian and Kungurian are represented by an advanced species of Durhamina and the very advanced durhaminid, Sandolasma.

Newly described species are: Durhamina primitiva, D. snyderi, Sandolasma perplexa, Heintzella davydovi, Paraheritschioides nevadaensis, and Wilsonastraea fraseri.

Machaeridians are marine Palaeozoic fossils, known from sediments of early Ordovician to mid Permian age (Bengtson, 1978; Cooper and Grant, 1972; Kaasa, 1992). Rare, completely articulated specimens reveal that they were long, slender, bilaterally symmetrical animals, covered by a dorsal scleritome comprising longitudinally arranged series of calcite sclerites (e.g., Adrain et al., 1991; Högström and Taylor, 2001a, 2001b). However, most known machaeridians, including those described in this paper, comprise isolated disarticulated sclerites. Until recently, the taxonomic affinities of the group were uncertain, and historically they were assigned to a number of different phyla (e.g., see Adrain, 1992). However, the recent account of an exceptionally preserved specimen with soft tissue anatomy, from the Lower Fezouata Formation (Lower Ordovician, Tremadocian) of Morocco, now indicates that machaeridians were annelid worms (Vinther et al., 2008).

Recent advances in microcomputer technology have created many tools for image processing and analysis that are useful for paleontologic studies. Although the Journal of Paleontology is not the appropriate forum for reviews of products from the rapidly changing field of computer technologies, a brief introduction to techniques presently available for image processing and analysis, and their potential applications to the field, may be of value to paleontologists.

In downtown Richmond, Va., a highly diatomaceous deposit contains a diatom assemblage in which 87 taxa have been identified. The diatoms indicate that this sedimentary unit is correlative with Lithologic Unit 19 of the Choptank Formation of middle Miocene age. Also in Richmond, a sedimentary unit correlated with the Eastover Formation overlies the Choptank Formation and contains a sparse diatom assemblage in which 24 taxa have been identified. The diatoms in this upper deposit form an assemblage that is distinctive from that of the Choptank Formation and is of late Miocene age. Both diatom assemblages are dominated by taxa indicating deposition in a littoral or shallow neritic marine environment. Although reasons for differences in diatom diversity and abundance between the two formations are obscure, these differences appear to reflect the greater primary productivity of diatoms in middle Miocene than in later Tertiary time.

Two new kirkocystid mitrate stylophorans (Echinodermata, Homalozoa) and a new possible solute (Echinodermata, Homalozoa) are described from the Early Ordovician of the western United States. The mitrates are among the earliest members of their clade to appear near the beginning of the Ordovician Radiation. Anatifopsis ninemilensis new species comes from the Ninemile Shale in central Nevada and the McKelligon Canyon Formation in west Texas. Anatifopsis fillmorensis new species comes from the middle Fillmore Formation in western Utah and a Ninemile Shale equivalent limestone bed in southern Nevada. The possible solute Drepanocystis dubius new genus new species from the lower Wah Wah Limestone in western Utah, shows unusual morphology with an elongate theca and a long arm shaped like a sickle.

Acheilus Clark, 1924, is a kingstoniid trilobite, not a catillicephalid or an unrecognizable genus as previously thought. The catillicephalid Theodenisia Clark, 1948, is here restricted to those species in which the axial furrows terminate at the 4s furrow and which lack a preglabellar furrow. Peracheilus n. gen. is proposed as a replacement name for the catillicephalid Acheilus Raymond, 1924. It includes those species previously assigned to Theodenisia in which the axial furrows continue past the 4s furrow to join a narrow preglabellar furrow. Acheilus, Theodenisia, and Peracheilus occur in the Late Sunwaptan of North America; Theodenisia also occurs in the early Ibexian.

Herein is reported the first occurrence of ostracodes from the Iapó Formation, an uppermost Ordovician unit of the Rio Ivaí Group in the Paraná basin, Brazil. Two ostracode species were identified in the Três Barras Farm section: Harpabollia harparum (Troedsson, 1918) and Satiellina paranaensis Adôrno and Salas in Adôrno et al., 2016 were recovered from dropstone-bearing shale overlying glaciogenic diamictites, a feature typical of Hirnantian (uppermost Ordovician) strata throughout Gondwana. The taxonomy of the Genus Harpabollia, as well as its type species Harpabollia harparum, was reviewed, and emended and new diagnoses were respectively proposed for each taxon. Occurrences of Harpabollia harparum and Satiellina species were common in areas influenced by cold waters. Additionally, the occurrence of Harpabollia harparum, an index species to the uppermost Ordovician of several stratigraphic units in Baltica and southern Gondwana, allowed us to infer a Hirnantian age for the deposits of the Iapó Formation. Other than being associated with Harpabollia harparum in Iapó Formation of the Paraná basin, Satiellina paranaensis is also found in lower levels of the Vila Maria Formation; therefore, these are also considered Hirnantian in age. Above these lower levels of the Vila Maria Formation, a well-dated Rhuddanian (lowermost Llandovery, Silurian) palynomorph assemblage is observed within the formation. These occurrences are evidence of a continuous process of sedimentary deposition during the Ordovician–Silurian transition in the Paraná basin.

Archamphiroa jurassica was described by Steinmann (1930) from carbonate deposits of the Cordillera de los Andes in Mendoza, central Argentina (Arroyo Negro, confluent of Malargüe River), assigned to the Callovian stage. Based on the general morphology and the internal structure of the identified fragments, Steinmann considered them to belong to the coralline algae. Comparisons made with some fossil and extant corallines species led him to the conclusion that Archamphiroa jurassica closely resembles some species of the extant genus Amphiroa.

The dorsal cups of 17 calceocrinid species illustrate the relations between ontogeny and phylogeny for this unique family. Paedomorphosis in conjunction with increasing adult body size comprises the dominant pattern. During evolution, the plate structure of the dorsal cup was rearranged so that the hinge of advanced crinoids resembles the juvenile configuration of more primitive species. Consideration of allometric equations dealing with the size and shape of the dorsal cup and hinge suggests that most changes were caused by displacements of the initial intercepts and offsets of timing in development. The growth of the hinge moment of typical taxa produces hinges that are functionally equivalent in adult crinoids of different body sizes.

Baesemann (1973) erected the genus Aethotaxis to accommodate morphologically distinctive conodont elements from the Pennsylvanian (Missourian) of northeastern Kansas. By chance we have recently discovered that the name is preoccupied by a notothenioid perciform fish Aethotaxis DeWitt, 1962. Thus, in accordance with Article 60 of the International Code of Zoological Nomenclature (1999), we propose the name Ubinates nomen novum as a replacement for Aethotaxis Baesemann, 1973, not Aethotaxis DeWitt, 1962. Ubinates derives from the Latin ubi, meaning where (interrogative), and nates, meaning rump; this refers to the fact that it is not known which, if any, of the elements presently assigned to species of Ubinates occupied the posterior positions in the apparatus. The type species of Ubinates is U. advena by original designation (Baesemann, 1973).

The Nayband Formation is one of the best known sedimentary units in central Iran. The type section consists of a thick succession of shale, siltstone, reef limestone and sandstone that is subdivided into five distinct members: Gelkan, Bidestan, Hoz-e-Sheykh, Howz-e- Khan and Qadir. Abundant and well-preserved framework-building scleractinian corals are included among the macrofossils of the Nayband Formation; these corals characterize the formation and are the subject of this study. The Hassan-Abad section, located in northeast Iran in Lute Block (northwest of Ferdows city), was chosen for detailed study and sampling. Analysis of sedimentary lithofacies and faunal assemblages in the Bidestan and the Howz-e-khan members indicate both biostromal and biohermal characters for the former shallow-water patch reefs and support a Norian to Rhaetian age. The useful biostratigraphic hydrozoan Heterastridium conglobatum was studied along with 14 taxa of scleractinian corals: Stylophyllopsis rudis, Distichophyllia norica, Paradistichophyllum dichotomum, Retiophyllia frechi, Retiophyllia norica, Retiophyllia robusta, Chondrocoenia schafhaeutli, Chondrocoenia ohmanni, Astraeomorpha crassisepta, Astraeomorpha confusa, Astraeomorpha minor, Procyclolites triadicus, Pamiroseris rectilamellosa, and Eocomoseris ramosa. These fossils clarify the stratigraphy of the Nayband Formation, as well as provide new information on the patch reefs and the framework constructors of these reefs.

Dianchungosaurus lufengensis was erected on the basis of fragmentary isolated jaw elements (a left premaxilla and left and right partial lower jaws) from the Lower Lufeng Formation (Lower Jurassic) of Yunnan Province, China. Yang referred Dianchungosaurus to the Heterodontosauridae (Ornithischia, Ornithopoda), as several features appeared to indicate affinity with the southern African genus Heterodontosaurus. However, reexamination of the type material demonstrates that the holotype specimen of Dianchungosaurus represents a chimaera of prosauropod dinosaur and mesoeucrocodylian remains: the mesoeucrocodylian premaxilla is distinctive and allows the genus to be diagnosed on the basis of several autapomorphic features. Revision of this genus thereby invalidates the only reported occurrence of a heterodontosaurid dinosaur from Asia.

The skull and mandible of Nothodipoides Korth are described. There are a number of adaptations present that are shared with other rodents with tooth-digging behavior (procumbent, elongated, and flattened incisors; anteriorly tilted occipital; strongly arched upper diastema). A new tribe of Castoroidinae, Nothodipoidini, is proposed for Nothodipoides and Microdipoides Korth and Stout, based on the fossorial adaptations of the skull, and their generally smaller size.It appears that fossorial adaptations have occurred in castorids at least three times: the Palaeocastorinae (Whitneyan through Arikareean), the primitive beaver Migmacastor (Arikareean), and the Nothodipoidini (late Barstovian through the Clarendonian).

A new agriochoerid, Protoreodon walshi new species, from the middle Eocene Santiago Formation, San Diego County, California, is described from the Jeff's Discovery and Rancho del Oro local faunas, considered to be late Uintan in age. It differs from most other species of Protoreodon in having an undivided P4 para-metacone and a P3 protocone connected to the paracone by a buccolingual crest. Associated postcranial material is abundant and well preserved. The postcranial skeleton shows several features which probably represent the primitive oreodont condition, including closely appressed metapodials, hoofed ungual phalanges, the lunar in broad contact with both the magnum and the unciform in anterior view, and having the magnum larger than the trapezoid.

Two specimens of a larger morph, Protoreodon cf. walshi, show a different P3 morphology and might represent another new species. Diversity of agriochoerid oreodonts in California is at least as high as has been reported for the Vieja Group of Texas, although not as high as in the Uinta Basin of Utah, where the genus Diplobunops is also present.

We report new specimens of the Plotopteridae from Washington State (USA), an area where these flightless seabirds underwent significant diversification during the late Eocene and Oligocene. To date, five plotopterid species from western Washington have been formally named. Specimens previously assigned to Tonsala buchanani Dyke, Wang, and Habib, 2011 belong to at least two, but probably even three, different species. One of these, the large-sized “Whiskey Creek specimen” from late Eocene deposits mapped as the Makah Formation, is the oldest known plotopterid and is here tentatively assigned to ?Klallamornis clarki Mayr and Goedert, 2016. Another specimen originally referred to T. buchanani is also likely to belong to a different species and is among the most substantial records for North American plotopterids. We formally transfer T. buchanani to the taxon Klallamornis and show that the only unambiguously identified specimen of the species—the holotype—is currently poorly diagnosed from Klallamornis abyssa Mayr and Goedert, 2016, which is from coeval strata of the Pysht Formation. Although the holotype of K. abyssa is larger than that of K. buchanani, there remains a possibility that plotopterids were sexually dimorphic in size. We describe the first ungual phalanx of a plotopterid, which is referred to K. buchanani, and report previously unknown elements of the large ?K. clarki and the first records of this species from the Lincoln Creek Formation. Current data indicate that plotopterids originated in the middle or late Eocene on islands off western North America, and we hypothesize that the radiation of these birds in the North Pacific Basin may have been related to the evolution of kelp forests.

Four new species of colonial corals, one previously described coral, and two other unidentified species of coral have been recovered from the Baird Formation in the Klamath Mountains of northwestern California. The newly erected species are Heritschioides armstrongi n. sp., Pararachnastraea klamathensis n. sp., P. watkinsi n. sp., and P. kabyaiensis n. sp. These corals are associated with the fusulinids Millerella marblensis Thompson, 1944, Paramillerella Thompson, 1951, and Pseudostaffella Thompson, 1942, emend Groves, 1984, suggesting an early Atokan (Bashkirian) age. Both the coral and foraminiferal faunas bear a resemblance to those of similar age in the Brooks Range, Alaska, which could suggest geographic proximity between the two terranes at that time. These corals also represent the earliest known occurrence of the Family Durhamididae.

Twenty four species of Cancellariidae belonging to eleven genera occurring in the Neogene Bocas del Toro assemblages, Caribbean Panama, are discussed and figured. The following seven species are described as new: Cancellaria pilula n. sp., Cancellaria isabelae n. sp., Cancellaria stri n. sp., Cancellaria axelolssoni n. sp., Massyla corpulenta n. sp., Aphera trophis n. sp., Admetula valientensis n. sp. The cancellarid genus Charcolleria Olsson, 1942 is considered a synonym of Massyla H. Adams and A. Adams, 1854. Of the 24 species present in the Bocas del Toro, 12 are known also to occur elsewhere in the tropical American Neogene. This level of endemism is high, but not as high as that reported from other Tropical American Neogene assemblages, probably due to the very central geographic location within the Gatunian Province of the Bocas assemblages.