Several specimens of the gigantic new species, Wewokella costata, have been recovered from the Upper Missisippian Hartselle Sandstone of Marshall County, east of Huntsville, in northeastern Alabama. The large sponges have flutted columnar growths and basic skeletons of triactines that are grossly encrusted or overgrown by calcium carbonate to produce massive fused skeletons. These are the oldest and largest specimens of Wewokella yet certainly identified. Wewokella costata has a skeleton with reduced numbers of triactines, but with extensive calcareous cement. The species could be in the lineage leading to the Inozoida Rigby and Senowbari-Daryan, 1996, which have spicule-free skeletons of sphaeroidal aragonite.

The upper Lower Carboniferous, Serpukhovian (=Chesterian) productide brachiopod genus Gondolina, from China, is made the type for the new subfamily Gondolininae in the Aulostegidae. Sectioned specimens reveal an unusual posterior dorsal flap of shell partially covering the ventral interarea.

The Triassic terebratulid brachiopod Coenothyris frequently displays preserved color patterns; such patterns have commonly been recorded from Paleozoic terebratulid brachiopods. Despite the frequency with which color patterns are preserved in Coenothyris, there has been no recent investigation of the cause and significance of this phenomenon. Shell material is well-preserved; energy-dispersive spectroscopy and microprobe analysis has been unable to detect compositional differences between colored and noncolored shell. This supports the organic origin of the color patterns as suggested for Devonian terebratulids by Richter (1919); color patterns originate from organic pigment in the primary shell layer.

Three subtypes of radial color banding are identified: subtype A with a relatively large number (up to 80) of delicate color bands on each valve; subtype B with fewer and generally wider color bands (less than 20) on each valve of adult specimens; subtype C with faint to fairly wide but very short color bands along the anterior margin (ranging from a few to more than 50 in number). Serial sections prepared from subtypes A and B confirm their congeneric status.

As shell form (length/width/thickness ratio) and maximum size varies, color pattern types differ in various stratigraphic horizons and also in isochronous populations from different geographic localities, indicating different facies. However, the variation in color patterns is not due to systematic differences at the species or subspecies level but rather reflects a tendency among Coenothyris vulgaris to respond to different environmental parameters. This variation in color patterns is ecophenotypic.

Juvenile specimens of the short-looped terebratulid brachiopod genus Pseudorhaetina Sandy have been investigated by the use of transverse serial sections. Internal structures indicate a simple brachidium (loop) is present with long flanges in adult specimens; the brachidium is approximately half the length of the dorsal valve; there is no complex loop metamorphosis in the central cavity of the brachiopod (i.e., no median septum). This combination of characters presents a taxonomic problem—Pseudorhaetina can neither be referred with confidence to superfamily Terebratuloidea, nor superfamily Loboidothyridoidea. Consequently Pseudorhaetina is, for the time being, assigned to a new and as yet unnamed superfamily representing a previously unrecognized part of the post-Paleozoic recovery and reradiation of Mesozoic articulate brachiopods (Rhynchonellata of Williams et al., 1996).

A new actinocerid genus, Kobayashiceras, is defined on the basis of Kobayashiceras gifuense new species from the Lochkovian (Early Devonian) of the Fukuji Formation, central Japan. This genus shares with known actinocerids in the apical shell morphology, but is diagnosed by its orthocerid like stenosiphonate form in the adoral shell. Its taxonomic and paleobiogeographic implications are discussed.

Three species of Karakaschiceras, K. attenuatus (Behrendsen, 1892), K. neumayri (Behrendsen, 1892), and K. lycoris (Leanza and Giovine, 1949), and one species of Neohoploceras, N. arnoldi (Pictet and Campiche, 1860), are described and figured from the Valanginian strata of the Neuquén basin in west-central Argentina. The large collection of fossils available for study shows wide intraspecific variation regarding ornament and whorl section in Karakaschiceras neumayri and Neohoploceras arnoldi, casting some doubts on the current systematics applied to species of these genera. The biostratigraphic position of the four species in the Neuquén basin corresponds to the Karakaschiceras attenuatus Subzone of the Olcostephanus atherstoni Zone. This subzone is correlated with the Mediterranean Karakaschiceras inostranzewi and Saynoceras verrucosum zones of Europe at the base of upper Valanginian sections.

A phylogenetic analysis was used to determine evolutionary relationships within the Early Cambrian superfamily Olenelloidea Walcott, 1890. Phylogenetic patterns within the suborder Olenellina Walcott, 1890, which contains the Olenelloidea and the Fallotaspidoidea Hupé, 1953, are also discussed. The Olenelloidea are monophyletic, and synapomorphies uniting them include the condition of the ocular lobes where they intersect the frontal lobe of the glabella, and the condition of the lateral margins of the glabellar lobes. In contrast, taxa formerly assigned to the Fallotaspidoidea are shown to represent a paraphyletic grade of several genera, some more closely related to the Olenelloidea, and some more closely related to the Redlichiina Richter, 1933. Seventy-nine exoskeletal characters were coded for 26 taxa within the Olenellina. These included 22 ingroup Olenelloidea and four outgroup taxa that have traditionally been assigned to the Fallotaspidoidea. When subjected to parsimony analysis these character data yielded a single most parsimonious cladogram that provides an hypothesis of relationship for the generic clades within the superfamily. Two new genera are recognized herein, Fritzolenellus and Lochmanolenellus. It has been argued that genetic flexibility was so great and trilobite morphology was so plastic in the Early Cambrian that suprageneric classification of Early Cambrian trilobites is precluded. Although levels of intraspecific variability may have been slightly higher in the Early Cambrian relative to the mid Paleozoic, based on the extent of polymorphic character codings, it was not so high as to obviate attempts at recovering phylogenetic structure in a major clade of Early Cambrian taxa. In addition, the consistency index recovered by this analysis is not unduly low for a phylogenetic database of this size. The phylogenetic analysis also has bearing on patterns of allometric heterochrony, which have often been held to be significant in Early Cambrian trilobites. The paedomorphic retention of advanced genal spines into the adult probably evolved at least four times. Three of the episodes can be best described as neoteny, the fourth, as progenesis. Finally, based on the phylogeny, it is likely that rates of speciation in trilobites may have been two to three times higher in the Early Cambrian than in the mid Paleozoic.

The arthropod macrofauna from the Middle Member of the lithographic limestones of the Tlayúa Formation, in quarries at Tepexi, México, is comprised of marine and nonmarine components. Marine taxa include a new species of flabelliferid isopod, a new genus and species of an anomuran, and a new genus and species of a brachyuran crab. Remains of an arachnid and an odonate nymph represent nonmarine constituents. Previous paleoenvironmental interpretations of a restricted lagoon, with periodic episodes of marine and freshwater influences are consistent with the nature of the arthropod fauna. Isopod remains, represented only by corpses, that resemble modern ectoparasites of fishes suggest that they are directly associated with the abundant fish remains found in the quarries, either as ectoparasites that released their hosts before they died or possibly as scavengers that fed on fish remains. The next most abundant arthropods are the crabs, most of which are corpses, suggesting that this group lived in or very near to the depositional site of the Tlayúa Formation. Based upon the new fossil material, the stratigraphic range for the Aeglidae has been extended to span Albian to Holocene time. Extant representatives of this family inhabit fresh water environments of South America.

Based on material of the Upper Cambrian of Sweden the internal structure of proto-, para- and euconodonts has been investigated. The protoconodontids Gapparodus and Gumella show some special development of the median unit of the skeletal tissue. In Gapparodus, long, parallel-running lamellae suggest a continuous growth, even of previously secreted lamellae, until their eventual outcropping. In Gumella the fibrous median layer decreases considerably during growth until its complete reduction, which coincides with the disappearance of the posterior wall. Paraconodonts also produced several specialities in their mode of growth. Elements with lateral processes such as Proacodus and Serratocambria developed by allometric growth. The lamellae are much more widely spaced in the process than in the main cusp to attain the required length of the former. In Serratocambria additional lamellae are inserted in the process. Thin sections of tricuspidate westergaardodinids reveal paraconodontid growth with lamellar remains in the tip of the median denticle, which are isolated from the growth lines in the lateral denticles. Based on this observation a hypothetical growth model explains the lamellar development as a result of stress and strain. The Ordovician euconodontid Chosonodina clearly shows white matter and is thus unrelated, but homeomorphic to Westergaardodina. Cambropustula from the lower Upper Cambrian is the oldest euconodont yet but it lacks white matter. The latter was an evolutionary novelty, which progressively developed in the euconodont line.

The systematic position of conodonts is briefly discussed; the studied material cannot contribute to the hypothesis of neural crest derived skeletal tissue.

Gondolella pohli new species assemblages, from the Desmoinesian of Illinois, confirm that the initial apparatus reconstruction of the conodont genus Gondolella was incomplete and support later reconstructions based on discrete elements.

Gondolella pohli is the first species of a biostratigraphically important conodont genus to be based primarily on assemblages and to be placed within a known phylogeny. The 43 assemblages confirm the presence of seven distinct element types in the Gondolella apparatus and permit the reconstruction of each of these to a greater degree than previously possible. Because the assemblages are probably all fecal, the apparatus of the closely related Neogondolella is used to interpret the apparatus plan—the position and identity of the 15 elements—single pairs of Pa, Pb, M, Sb1, and Sb2 elements, two pairs of Sc elements, and an unpaired bilaterally symmetrical Sa element in the Gondolella apparatus. Using the similarity of the latter to the apparatuses of the better known ozarkodinids, we infer a three-dimensional fanlike apparatus architecture for the prioniodinid Gondolella. Gondolella is apparently restricted to the Pennsylvanian and probably evolved in the Early Pennsylvanian from the Idioprioniodus-Embsaygnathus lineage by loss of the Pa element posterior process and by remodelling of the other apparatus elements. Some species in the Idioprioniodus-Gondolella lineage are atypical among prioniodinids in having developed a Pa element platform; the lineage is also noteworthy because both ancestor and descendant inhabited low-energy, low pH environments during the Pennsylvanian.

The hitherto poorly known forefin of Chensaurus chaoxianensis (Ichthyosauria) from the Lower Triassic (Spathian) is redescribed on the basis of the holotype and two new specimens. The humerus resembles that of Utatsusaurus hataii but is distinctive in having an emarginated anterior margin. The anteroproximal prominence of the radius is well developed, unlike that of other ichthyosaurs. All three specimens have five metacarpals and many phalanges, but only three carpals, which are identified as the ulnare, intermedium, and fourth distal carpal. These specimens show that delayed mesopodial ossification occurred in ichthyosaurs, at least in an early evolutionary stage. Because delayed mesopodial ossification is common among diapsids and is unknown in Jurassic ichthyosaurs, it was lost during the evolution of the Ichthyosauria. The osteogenic developmental axis appears to have continued into the fourth digit, as in other amniotes. The ossification pattern provides conclusive evidence to support the suggestion that the basal element of the fifth digit in Early Triassic ichthyosaurs is a metacarpal, rather than a carpal.

Four new fossil mammalian assemblages are now recognized from west central Nevada. The late Barstovian or earliest Clarendonian Eagle-Picher Mine Site assemblage was recovered from the upper sedimentary member of the ?Desert Peak Formation exposed in the northeastern Virginia Range of Storey County and consists of the following taxa; Camelidae, gen. indet. and Rhinocerotidae, gen. indet. The ?Clarendonian Churchill Valley Local Fauna and Clarendonian or Hemphillian Churchill Narrows Site assemblage were recovered from correlatives of the type Coal Valley Formation exposed along the southern flanks of the Virginia Range and in the vicinity of the Churchill Narrows area, respectively. The Churchill Narrows Site assemblage consists of the following taxa: Rhinocerotidae, gen. indet.; Camelidae, gen. indet. (small-sized); and Camelidae, gen. indet. (large-sized). The Churchill Valley Local Fauna consists of the following taxa: Leporidae, gen. indet.; cf. Mustelidae, gen. indet.; Teleoceras sp. indet.; Dinohippus sp. indet.; Camelidae, gen. indet. (small-sized); and Camelidae, gen. indet. (large-sized). The late Hemphillian Silver Springs Local Fauna was recovered from outcrops of the Truckee Formation exposed in the southeastern Virginia Range of Lyons and Churchill counties. It is the first biostratigraphically datable fauna from the upper member of the formation and consists of the following taxa: Lepoides cf. lepoides; Hypolagus ringoldensis; Hypolagus tedfordi; Hypolagus sp.; Pliotaxidea sp. indet; Teleoceras sp. indet.; Dinohippus sp. indet.; Hemiauchenia vera; Camelidae, gen. indet. (medium-sized); and Antilocapridae, gen. indet.

Dental and postcranial remains of a donkey-sized, three-toed, primitive horse were collected from the “Undifferentiated Miocene” Ecor Rouge Sand (which underlies the widespread Citronelle Formation) from the Mauvilla site in southern Alabama. These fossils probably pertain to a single individual of Protohippus gidleyi Hulbert, 1988. This represents an exceedingly rare occurrence of a late Tertiary land mammal from the central Gulf Coastal Plain and allows comparisons with better-known, contemporaneous land-mammal assemblages from Florida. Based on the known biochronology of Protohippus gidleyi from other localities, and the stratigraphic position of the Mauvilla record, the age of: 1) the Ecor Rouge Sand is late Miocene (latest Clarendonian to early Hemphillian landmammal “age”), between 9.0 to 6.5 Ma; and 2) the overlying Citronelle Formation near its type locality in southern Alabama is therefore late Miocene or younger.

Tidal rhythmites of the Tonganoxie Sandstone Member (Stranger Formation, Douglas Group) at Buildex Quarry, eastern Kansas, contain a relatively diverse ichnofauna. The assemblage includes arthropod locomotion (Dendroidichnites irregulare, Diplichnites gouldi types A and B, Diplopodichnus biformis, Kouphichnium isp., Mirandaichnium famatinense, and Stiaria intermedia), resting (Tonganoxichnus buildexensis) and feeding traces (Stiallia pilosa, Tonganoxichnus ottawensis); grazing traces (Gordia indianaensis, Helminthoidichnites tenuis, Helminthopsis hieroglyphica); feeding structures (Circulichnis montanus, Treptichnus bifurcus, Treptichnus pollardi, irregular networks), fish traces (Undichna britannica, Undichna simplicitas), tetrapod trackways, and root traces. The taxonomy of some of these ichnotaxa is briefly reviewed and emended diagnoses for Gordia indianaensis and Helminthoidichnites tenuis are proposed. Additionally, the combined name Dendroidichnites irregulare is proposed for nested chevron trackways. Traces previously regarded as produced by isopods are reinterpreted as myriapod trackways (D. gouldi type B). Trackways formerly interpreted as limulid crawling and swimming traces are assigned herein to Kouphichnium isp and Dendroidichnites irregulare, respectively.

Taphonomic analysis suggests that most grazing and feeding traces were formed before the arthropod trackways and resting traces. Grazing/feeding traces were formed in a soft, probably submerged substrate. Conversely, the majority of trackways and resting traces probably were produced subaerially in a firmer, dewatered and desiccated sediment.

The Buildex Quarry ichnofauna records the activity of a terrestrial and freshwater biota. The presence of this assemblage in tidal rhythmites is consistent with deposition on tidal flats in the most proximal zone of the inner estuary, between the maximum landward limit of tidal currents and the salinity limit further towards the sea.