The distinctive trace fossil Chubutolithes gaimanensis n. ichnosp. occurs in Casamayoran (early Eocene) and Colhuéhaupian (late Oligocene) alluvial rocks of the Sarmiento Formation in eastern Chubut Province, Argentina. Though known for nearly 70 years, its origin has remained obscure. Examination of new specimens and comparisons with modern analogs demonstrate that specimens of Chubutolithes represent the fossil nests of a mud-dauber (Hymenoptera: Sphecidae). Virtually identical nests are constructed today by mud-daubers in areas as disparate as southern Santa Cruz Province, Argentina, and Nebraska, confirming that quite similar trace fossils can be produced by several different taxa in a higher taxonomic clade. No satisfactory ethological term exists for trace fossils that, like Chubutolithes, were constructed by organisms above, rather than within, a substrate or medium. The new term aedificichnia is proposed.

Chubutolithes occurs in alluvial paleosols and is associated with a large terrestrial ichnofauna. These trace fossils include the nests of scarab beetles, compound nests of social insects, and burrows of earthworms.

Large trace fossils attributed to the ichnogenus Psilonichnus (Fürsich) have been identified in subtidal sediments of the Red Crag Formation (late Pliocene) of Walton-on-the-Naze, Essex, U.K. The traces are vertical or inclined, tapering cylindrical structures, occasionally branched, up to 2.3 m long. The structures are mud-rich relative to the surrounding sediment and their fills often show a spiralling grain fabric. The ichnogenus Psilonichnus has formerly been attributed to the burrowing activities of intertidal and supratidal crab species. The known fossil crab assemblage of the Red Crag contains no deep burrowing species. The traces are thus attributed to other crustaceans, possibly thalassinidean shrimps. The occurrence indicates that Psilonichnus may have a greater palaeoenvironmental range than previously realized.

Lidaconus palmettoensis n. gen. and sp. is a recently discovered fossil from the Lower Cambrian Harkless Formation (Bonnia–Olenellus Zone) in Esmeralda County, Nevada. The conoidal fossils were originally calcareous and have been replaced by silica. The cones are distinctive in their consistent morphology, the presence of weak annulations, and the lack of any internal structures such as septa, tabulae, or dissepiments. Because of the paucity of diagnostic characters due to the simple morphology and the lack of original microstructure, taxonomic affinities are uncertain.

Modifications of primitive astogenetic patterns were central to the origin of bifoliate Peronopora. Outgroup comparison with Prasopora indicates that fundamental events in the former's origin included vertical growth of basal lamina skeleton to form the median lamina and heterochronic modifications of early and later-stage astogeny. Heterochronic modifications of early astogeny included acceleration of budding rates in the ancestrular disc, disc enlargement, and reduction of the basal expansion. Later-stage heterochronic modifications included reduction of zooecial length and width of “endozonal” growth and parallel orientation of cystiphragms about maculae. Also important were “2-D” budding in longitudinal ranges and a unique mode of secondary frond formation. Paedomorphosis resulted in constraints on zoarial form, autozooecial morphology, cystiphragm patterning, and increased colonial integration. Coordination of early and later-stage astogenetic events suggests developmental integration linked to median lamina formation. Heterochronic modifications are inferred to have been products of spatial competition in early astogeny and competitive avoidance and resource exploitation in later astogeny. Restricted biogeographic distribution and characteristics of the ancestrula suggest that the larvae of bifoliate Peronopora were nonplanktotrophic.

A shared derived suite of characters including the median lamina unite the bifoliate Peronopora clade. Results of cladistic analyses indicate that bifoliate Peronopora comprise a cohesive, statistically significant clade. Character analysis, phylogenetic results, and the restricted biogeographic distribution of bifoliate species support the hypothesis of a monophyletic bifoliate Peronopora clade of generic rank. The generic concept of Peronopora is revised and limited to bifoliate species.

The Richmondian (Upper Ordovician) strata in the Central Basin of Tennessee yield an abundant and diverse fauna of brachiopods. The section consists in ascending and conformable order of the “Arnheim” and Fernvale Formations.

The following species are described: Austinella kankakensis (McChesney), Diceromyonia tersa Wang, Glyptorthis insculpta maquoketensis Ladd, Hebertella occidentalis (Hall), Onniella meeki (Miller), Paucicrura quadrata (Wang), Pionodema alberstadti n. sp., Plaesiomys bellistriatus Wang, P. proavita (Winchell and Schuchert), Platystrophia acutilirata (Conrad), P. ponderosa Foerste, Rafinesquina sp., Retrorsirostra carleyi (Hall), Strophomena planumbona (Hall), Tetraphalerella neglecta (James), Thaerodonta recedens (Sardeson), and Zygospira modesta (Hall).

Faunal comparisons confirm correlations with the Cape Limestone of southeastern Missouri, the Maquoketa Formation of Iowa, the upper part of the Viola Formation of Oklahoma, the Aleman and Cutter Formations in West Texas, and the standard Richmond section. The fauna in Tennessee connects the provincial Richmond in the Ohio Valley with the western faunas.

Concepts of the family Hyolithidae Nicholson fide Fisher and the genera Hyolithes Eichwald and Orthotheca Novak have been expanded through time to encompass a variety of morphologically dissimilar shells. The Hyolithidae is here considered to include only those hyolithid species which have a rounded (convex) dorsum; slopes on the dorsum are inflated, and the venter may be flat or slightly inflated. Hyolithes encompasses species which possess a low dorsum and a prominent longitudinal sulcus along each edge of the dorsum; the ligula is short and the apertural rim is flared. The emended concept of Orthotheca includes only those species of orthothecid hyoliths which have a subtriangular transverse outline and longitudinal lirae covering the shell on both dorsum and venter.

Eighteen species of Hyolithes and one species of Orthotheca from the Appalachian region and Western Interior were reexamined in light of more modern taxonomic concepts and standards of quality for type material. Reexamination of type specimens of H. similis Walcott from the Lower Cambrian of Newfoundland, H. whitei Resser from the Lower Cambrian of Nevada, H. billingsi Walcott from the Lower Cambrian of Nevada, H. gallatinensis Resser from the Upper Cambrian of Wyoming, and H. partitus Resser from the Middle Cambrian of Alabama indicates that none of these species represents Hyolithes. Hyolithes similis is here included under the new genus Similotheca, in the new family Similothecidae. Hyolithes whitei is designated as the type species of the new genus Nevadotheca, to which H. billingsi may also belong. Hyolithes gallatinensis is referred to Burithes Missarzhevsky with question, and H. partitus may represent Joachimilites Marek. The type or types of H. attenuatus Walcott, H. cecrops Walcott, H. comptus Howell, H. cowanensis Resser, H. curticei Resser, H. idahoensis Resser, H. prolixus Resser, H. resseri Howell, H. shaleri Walcott, H. terranovicus Walcott, and H. wanneri Resser and Howell lack shells and/or other taxonomically important features such as a complete aperture, rendering the diagnoses of these species incomplete. Their names should only be used for the type specimens until better preserved topotypes become available for study. Morphology of the types of H.? corrugatus Walcott and “Orthotheca” sola Resser does not support placement in the Hyolitha; the affinities of these species are uncertain.

Two new species of worm tubes referable to the genus Onuphionella occur in Lower Cambrian strata in eastern California and western Nevada. Onuphionella durhami n. sp. is found in the Campito Formation (in pre-trilobite strata, in the Fallotaspis and, possibly, the Nevadella Zones) and O. claytonensis n. sp. occurs in the Middle Member of the Poleta Formation (Nevadella Zone). The unusual tubes are armored with an imbricated coat of mica flakes, reminiscent of the modern genus Owenia. The lowest occurrence of Onuphionella in western North America corresponds closely with the lowest occurrence of the genus in the Baltic region, indicating that correlations between the two regions are not greatly in error.

Four trilobite species are present in the Gilmore City Limestone (Kinderhookian–Osagean) of Humbolt County, Iowa. The most common trilobite taxa, Perexigupyge hodgesi n. gen. and sp. and Perexigupyge gerki n. gen. and sp., make up the greatest percentage of the trilobite population. Two other species are known from fragmentary cranidia and are assigned to the genera Richterella and Proetides. Prior to the description of these forms, the only trilobite previously described or illustrated from the Gilmore City Limestone was a cranidium of Proetides insignis (Winchell) from the type area.

The Gilmore City Limestone in Humbolt County, Iowa, represents deposits associated with an oölitic sand-shoal environment, including washover-lobe and back-shoal deposits. Morphologic attributes exhibited by the Gilmore City Limestone trilobites, such as low relief and vaulting to the exoskeleton and subdued surface ornamentation, may have been adaptations that enabled them to inhabit current-swept shoal environments. Conversely, coarsely tuberculate forms may have used the tubercules as a mimic of the surrounding coarse-grained sediment or to strengthen the exoskeleton.

Linuparus (Linuparus) korura n. sp. is described from Bortonian (middle Eocene) rocks in Otaio Gorge, South Canterbury, New Zealand. This discovery represents the first occurrence of the genus in New Zealand and the first notice of a fossil occurrence of the subgenus which is represented by three modern Indo-Pacific species. Comparison of key morphological descriptors suggests that L. korura is related to L. scyllariformis and L. trigonis. A stridulatory mechanism, similar to that seen on modern Linuparus, is described for the first time from the fossil record.

The Mesozoic history of Lepidoptera and Trichoptera is reviewed and their phylogeny traced back to early Mesozoic specialized Permochoristidae Mecoptera. Queensland emerges as the center of origin for the earliest Lepidoptera and Trichoptera and is also the region where the first lepidopteran hostplants, primitive dicot angiosperms, arose from Glossopteridae, probably at the Triassic–Jurassic boundary. Protomecoptera evolved from extinct Protoblattodea (not Neuroptera) during Late Carboniferous or Early Permian time. The first Lepidoptera, terrestrial Agathiphagidae, evolved from aquatic Necrotauliidae Trichoptera probably at the close of the Triassic when an extreme drought dried up many streams. The very small size of Amphiesmenopteran Mecoptera and the first Trichoptera and Lepidoptera fossils obeys Cope's Rule.

Fourteen oribatid mite fossils have been recovered from a terrestrial Devonian deposit near Gilboa, New York; they allow an approximate doubling of the known age of the group. Two species are represented by specimens complete enough to allow descriptions. Protochthonius gilboa n. gen. and sp. is the earliest derivative known member of the Enarthronota, and comprises the monobasic new family Protochthoniidae. Devonacarus sellnicki n. gen. and sp. also represents a monobasic new family, Devonacaridae; it may also be an early derivative enarthronote mite, but its relationships are uncertain. Two other species are represented at the site, but meaningful descriptions are not possible with available material.

A largely new, Early Mississippian blastoid fauna is described from the Fort Payne Formation of south-central Kentucky and north-central Tennessee. The fauna consists of nine species assigned to eight genera, including four new genera and six new species. The fauna includes Hadroblastus breimeri n. sp., Granatocrinus granulatus (Roemer), Dentiblastus macurdai n. sp., Deliablastus cumberlandensis n. gen. and sp., D. tribulosus n. gen. and sp., Xyeleblastus magnificus n. gen. and sp., Perittoblastus liratus n. gen. and sp., Euryoblastus veryi (Rowley) n. gen., and an unidentifiable basal circlet that may represent a phaenoschismatidid. All spiraculates belong to the Granatocrinidae.

The Fort Payne Formation has the most diverse blastoid fauna known between the middle Osagean blastoid extinction and the Permian. Diversification immediately after the middle Osagean extinction is recorded in the Fort Payne and is largely a diversification of the Granatocrinidae.

Orbitremites grandis Rowley (1902) is an internal mold from the Fort Payne Formation. This specimen cannot be identified and is designated as a nomen dubium.

The discovery of the arms of the disparid inadunate crinoid Ramseyocrinus Bates from the Arenig (Lower Ordovician) of Morocco extends the geographic range of this genus, previously only known from south Wales, United Kingdom, and the Montagne Noire, France. It is probable that the Moroccan specimen represents a new species. This is the first Lower Ordovician crinoid to be described from Africa.

A new species of Ptychocrinus, Ptychocrinus adamsensis, and dendrocrinid, genus and species undetermined, are described from the Lower Silurian (Llandovery) Brassfield Formation of Adams County, Ohio. Unlike previously recognized Ptychocrinus species, P. adamsensis has biserial arms. Accordingly, the generic concept of Ptychocrinus is broadened. Ptychocrinus adamsensis is the youngest North American species of Ptychocrinus. Ptychocrinus is not known from the Brassfield fauna that has been previously described from the Greene–Montgomery County area of Ohio.

A Campanian fish assemblage is described from the uppermost Blufftown Formation in western Georgia. Fifteen chondrichthyan and eight osteichthyan taxa are identified, virtually all for the first time from the region. The study area represented a transitional zone between the Atlantic and eastern Gulf of Mexico Coastal Plain Provinces during the Late Cretaceous, and shows faunal relationships with both.

A prominent anterior bulge on a ceratopsian dinosaur phalanx was examined for evidence of infection or stress (fatigue) fracture. The presence of a knife-slice type radiolucency, associated with periosteal reaction, was pathognomonic (diagnostic) for a stress fracture. Stress fractures have previously been recognized only in humans, racing greyhounds, and horses.

Middle and lower Ordovician gastropods have not previously been described from Alaska, and the genus Helicotoma Salter has not been reported from western and arctic North America with the exception of one locality in California (Rohr, 1980). Like many other Paleozoic gastropod genera, Helicotoma has several species assigned to it, but the species are often based on poor material and, in some cases, on a single specimen. This lack of knowledge of variation within the species as well as the detailed features of the shell make further interpretations of the gastropods difficult. The occurrence of relatively abundant, well-preserved Helicotoma specimens in Alaska is important for biogeographic and biostratigraphic studies of lower Paleozoic mollusks.

Although the burrows and trails in the Upper Ordovician rocks around Cincinnati, Ohio, have been fully documented and are well known (Osgood, 1970), comparatively little attention has been paid to the borers. Nevertheless, borers are very common in a variety of hard substrates in these rocks. These substrates include the skeletons of bryozoans, corals, and stromatoporoids (Palmer and Wilson, 1988), as well as cobbles and hardgrounds (Palmer, 1982; Wilson, 1985). By far the most common type of boring is the elongate tube Trypanites, which could have been made by a variety of filter-feeding worms. Trypanites is common on hard substrates throughout the lower Paleozoic (Palmer, 1982).

The pseudorthoceratid subfamily Macroloxoceratinae Flower, 1957, comprises a rare group of nautiloid cephalopods homeomorphic with the Actinoceratida in the development of a siphonal canal system. With the exception of Macroloxoceras Flower, 1957, from the Upper Devonian of Colorado and New Mexico, this subfamily has previously been reported only from the Mississippian of Europe. A specimen described herein from the late Viséan–?early Namurian Kennetcook Limestone of the Windsor Group of Nova Scotia, assigned to Campyloceras cf. C. unguis (Phillips, 1836), extends the range of the Macroloxoceratinae into the North American Mississippian. This discovery further provides new data on the complex siphonal morphology of this poorly known group of nautiloids, and supplements the recent documentation of the pseudorthoceratids in the Windsor Group cephalopod fauna (Edgecombe, 1987).

The trilobite Phacops rana has previously been documented in two life positions: horizontally outstretched and enrolled (Hall and Clarke, 1888). A specimen of Phacops rana was recovered in an unusual life position from the Windom Member of the Moscow Formation (Figure 1). It was collected from a borrow pit along Castle Hill Road, 1 km east of Earlville in Chenango County, New York. The trilobite appears to have burrowed tail first into the substrate, with only part of the cephalon and one or two thoracic segments exposed above the sediment surface. The orientation of the eyes indicate that the visual field was horizontal. The thorax angled into the substrate at an angle of approximately 50° from the horizontal, with the pygidium tilted dorsally relative to the thorax. Compaction effects appear to be slight. Because the specimen was found in situ, no doubt exists as to its orientation with respect to bedding. It is also evident from bedding plane surfaces that this trilobite had burrowed, and was not simply draped over an uneven substrate, as it intersects three bedding planes. There is no evidence of any object over which it could have been draped. No burrow trace, lining, or scratch marks are preserved. No other specimens of Phacops in this position have been reported.