Thermally unaltered conodont elements, brachiopods, and vertebrates were analyzed with reverse phase high profile liquid chromatography to locate and quantify amino acid remnants of the original organic matrix in the fossils. No consistent similarities in amino acid content were found in conodont taxa, and criteria based on organic residues appear to have no taxonomic significance in the fossils tested from these localities. However, hydroxyproline, an amino acid that is found in the collagen molecules of animals, as well as in the glycoproteins in the cell walls and reproductive tissues of certain plants, is represented in most taxa. The organic matter retained in the impermeable crowns of conodont elements might have been derived originally from a form of collagen. Biochemical analyses, correlated with histochemical tests, demonstrate that organic matter is an integral part of the hyaline tissue of the element crown and not the result of surface contamination. Tests of a range of vertebrate and invertebrate fossil hard tissues produced similar results. The analyses indicate that hyaline tissue in the conodont element crown is not a form of vertebrate enamel, which contains no collagen. Albid tissue, with little or no organic content, is not a form of vertebrate bone or dentine, both based on collagen and low in mineral. Although these results do not help to determine the phylogenetic affinities of conodont animals, they indicate that conodont elements do not contain hard tissues characteristic of vertebrate animals.

Cupulocrinus angustatus (Meek and Worthen, 1870) is common and widely distributed in the Maquoketa Formation of the northern midcontinent of the United States, and specimens are known from the Isotelus and Vogdesia Zones of the Elgin, the Clermont, Fort Atkinson, and Brainard Members. Cluster significance tests indicate that crinoids from all stratigraphic horizons are conspecific. The most numerous primibrachs are located in the A and B rays, whereas the C ray exhibits the fewest plates. The largest and smallest numbers of secundibrachs occur in the B and C rays, respectively. The number of brachs is independent of stratigraphic position and the size of the crinoids. Correlation coefficients for the numbers of brachs demonstrate that the arms are divided into two overlapping and covarying levels: the proximal arms from the primibrachs to tertibrachs, and distal arms ranging from the tertibrachs to quintibrachs. Growth of the aboral cup is generally isometric or roughly so. Conversely, the width:height ratios of brachs typically increase in progressively larger individuals. Similarly, most deposition of calcite on the columnals affects their width rather than height. The correlations for the aboral cup and its plates generally exceed those of brachs and stem plates. The contrasts in allometry and integration and coordination between the aboral cup versus the brachs and column are attributed to differences in basic geometry and developmental constraints. Similar patterns are seen in other Paleozoic and perhaps all or most crinoids.

The dicynodont anomodont Odontocyclops whaitsi, from the Late Permian Madumabisa Mudstone of Zambia, is redescribed and its phylogenetic relationships are considered. The genus is characterized by a two autapomorphies, elongate nasal bosses and a concave dorsal surface of the snout; it also possesses wide exposure of the parietals on the intertemporal skull roof, the presence of a postcaniniform crest, the absence of a labial fossa, and the presence of a dorsal process on the anterior ramus of the epipterygoid footplate. In addition, newly recognized specimens collected in South Africa extend the known geographic range of the genus and allow description of the humerus and scapula for the first time. Cladistic analysis of a data set including Odontocyclops and 18 other well-known South African dicynodont genera does not support the hypothesis that Odontocyclops is a close relative of Dicynodon or of Triassic dicynodonts such as Kannemeyeria. Instead, a close relationship with Oudenodon and Rhachiocephalus is proposed. The presence of Odontocyclops in South Africa and Zambia makes it potentially valuable for more precise biostratigraphic correlation between the sediments of the Karoo Basin and the Luangwa Valley.

Latest Early Cambrian continental slope deposition of the early Hatch Hill dysaerobic interval (new name, latest Early Cambrian—earliest Ordovician) is recorded by dark grey shales and turbidite limestones in the Bacchus slice at Ville Guay, Québec. Platform-derived microfaunas of the Bicella bicensis trilobite assemblage were transported into a dysoxic environment of the upper “Anse Maranda Formation,” and many organisms were buried alive. Phosphatization preserved a diverse skeletal fossil assemblage that includes four agnostid trilobites, echinoderm debris, and twenty small shelly fossil taxa. The latter include five helcionellids; Pelagiella Matthew, 1895b, classified herein as a gastropod; a bivalve (Fordilla Barrande, 1881); the brachiopod Linnarssonia taconica Walcott, 1887; two conodontomorphs; four hyoliths; and such phosphatic and calcareous problematica as Coleoloides Walcott, 1889, emend. Most small shelly fossil taxa, including Discinella micans Billings, 1872, range through much of the Olenellus Zone and Elliptocephala asaphoides assemblage interval. Trilobites allow a more resolved correlation into the uppermost Olenellus Zone. A comparable stratigraphy occurs in Cambrian—Ordovician slope facies of the Bacchus slice and the Giddings Brook slice in eastern New York. The “Anse Maranda Formation” correlates with the West Granville—Browns Pond—lower Hatch Hill formations in eastern New York and brackets two dysaerobic intervals (Browns Pond and early Hatch Hill). Sea-level change associated with the Hawke Bay regression between the Browns Pond and Hatch Hill onlap/dysaerobic intervals led to the longest period of oxygenated green shale and sandstone deposition on the east Laurentian slope in the late Early Cambrian-earliest Ordovician.

A species of the rudist bivalve genus Mexicaprina Coogan, 1973, from the mid-Cretaceous Mai Paso Formation of the Guerrero terrane, southwestern Mexico, is described as new: M. alata. At the type locality of this new species, a 6.5 m thick Mexicaprina-rich floatstone bed conformably overlies a taxonomically diverse build-up of reef corals. This type of facies relationship and implied faunal association has not been observed previously at any other site. Specimens of the type species, M. cornuta Coogan, 1973, also were found at the same locality, but 90 m stratigraphically below the lowest occurrence of M. alata. Compilation and detailed biostratigraphic analysis of the reported occurrences of Mexicaprina demonstrate that the age of the genus ranges from late Albian to early Cenomanian. However, most occurrences are late Albian and the Cenomanian age determinations are questionable and possibly late Albian also. The occurrence of species of Mexicaprina in the allochthonous Guerrero terrane, together with the relatively limited geographic distribution of the genus in the late Albian and early Cenomanian of the Gulf Coast of Mexico, Texas, and Honduras, indicates that this region of the Guerrero terrane was part of the Caribbean paleobiogeographic province during late Albian to early Cenomanian time. This occurrence also suggests that this portion of the Guerrero terrane was very close, possibly accreted, to the southwestern margin of North America by the close of the Early Cretaceous.

A recently discovered tetrapod-bearing locality (OMNH V1005) in the Upper Pennsylvanian Ada Formation of Oklahoma has produced the remains of six taxa: the pelycosaurian-grade synapsid Ophiacodon cf. mirus, an indeterminate sphenacodontian pelycosaur, the temnospondyl Eryops? sp., the rare diadectid Diasparactus zenos, and two unidentified taxa known only from jaw fragments. The skeletal material comprises an allochthonous assemblage transported by low-velocity currents prior to burial. Except for four articulated Ophiacodon vertebral segments, all fossil material recovered in situ was disarticulated. The bones were not exposed to prolonged periods of weathering prior to burial. OMNH V1005 records the first occurrence of Eryops, Diasparactus, and Ophiacodon from the Pennsylvanian of Oklahoma. The presence of Diasparactus zenos indicates that this species was not endemic to New Mexico, as formerly believed. An associated dentary provides the first well-preserved cheek teeth of Diasparactus zenos. Compared to other North American diadectid genera, these teeth resemble more closely those of Diadectes than those of Desmatodon. The occurrence of Ophiacodon mirus, which was previously known from Lower Permian strata of New Mexico, extends both the stratigraphic and geographic range of this species. The Ada assemblage resembles those found in Permo-Carboniferous deltaic deposits in the southwestern United States.

Sphenothallus Hall, 1847 is a widespread Paleozoic marine taxon that has been interpreted most recently as a tubiculous annelid or other ‘worm’ or as a thecate hydrozoan or scyphozoan cnidarian (e.g., Mason and Yochelson, 1985; Feldmann et al., 1986; Van Iten et al., 1992, 1996; Neal and Hannibal, 2000; Zhu et al., 2000). Members of this genus are characterized by a very gently tapered, finely lamellar apatitic tube bearing a closed subconical holdfast and a pair of robust longitudinal thickenings situated at the ends of the tube's greatest diameter (Zhu et al., 2000). Rarely, the tube exhibits an internal transverse wall that extends adaperturally along the inner surface of the tube proper and may also exhibit a subcylindrical terminal protuberance (Van Iten et al., 1992, figs. 5, 6). The transverse wall of Sphenothallus is essentially identical in gross morphology and microstructure to the schott (apical wall) of conulariids, an extinct group of thecate cnidarians (Van Iten, 1991, 1992a, 1992b; Jerre, 1994; Van Iten et al., 1996; Hughes et al., 2000) that may have been closely related to Sphenothallus (Van Iten et al., 1992). Clarke (1913, pl. 26, figs. 16-18; see also Van Iten et al., 1992, fig. 3) illustrated a compound specimen of S. sica consisting of numerous “daughter” tubes arranged in a highly regular manner (in opposition and evenly spaced) along a single, relatively large “parent” tube whose test wall appears to be confluent with the base of the “daughter” tubes. This compound specimen is distinctly different from the more common associations of epibiontic, holdfast-bearing Sphenothallus arranged in a less orderly fashion on Sphenothallus tubes or other shells (see for example Feldmann et al., 1986, fig. 2), and probably is best interpreted as a clonal colony. Sphenothallus tubes, both solitary and branched, are most similar to thecae of solitary and colonial hydrozoan and scyphozoan polyps, differing from these relatively delicate structures mainly in being mineralized and in bearing a pair of longitudinal thickenings. Like conulariids, Sphenothallus occurs in rocks originally deposited in a broad spectrum of marine facies (open carbonate shelf to restricted shale basin), but is perhaps most conspicuous in restricted basin and shelf slope facies represented by dark shales and lime mudstones.

Morphology is reviewed with special reference to the doublure and thoracic characters; a reconstruction of Richterarges aquilonius is used to suggest possible lichid anatomy. The relatively large hypostome and wide doublure, and the thorax with, or without, the strongly convex posterior pleural bands characterize lichids, in addition to the distinctive glabellar morphology. Relatively shallow furrows on the external surface form strong ridges on the visceral surface of the exoskeleton; apodemes are absent. Type specimens of species described by Schmidt, recently traced in Russian museums, are figured. Lichids differ from odontopleurids in morphology and anatomy, and are unlike Scutelluinae; accepted subfamilial divisions of Lichidae are reinforced by thoracic characters. A single lichid species is known in the early Tremadoc, in the early Middle Ordovician the main four subfamilies are recognised and are widespread; their ancestry and early diversification remain unknown.

A well-preserved crocodyliform specimen from the Maastrichtian or Paleocene of Mali preserves the braincase and posterior dermatocranium. It is referred to Dyrosauridae on the basis of several derived features (a prominent anterior process of the postorbital, discrete occipital processes on the exoccipitals, significant quadratojugal contribution to jaw joint) and tentatively referred to Rhabdognathus on the basis of supratemporal fenestra shape. The lacrymal and prefrontal are relatively short compared with those published for other dyrosaurids. The palatines border the internal choanae anteriorly, and the choanae are divided by a midline septum derived from the pterygoids. The prefrontal pillars are mediolaterally broad and contact the palate ventrally. One stapes is preserved in place. The basicranial pneumatic system is very unusual, in that the anterior and posterior branches of the median eustachian canal are both separate at the palatal surface, and the pterygoids form part of the border for the anterior branch. The lateral eustachian openings lie within fossae on the lateral surface of the braincase and face laterally, with a descending process of the exoccipital nearly intersecting the opening. The braincase and surrounding dermal bones are elongate anteroposteriorly, and the postorbital's posterior ramus extends along the posterodorsal margin of the infratemporal fenestra. The quadrate ramus projects ventrally. These observations clarify character optimizations in previous phylogenetic analyses of Crocodyliformes.

All species of Barycrinus from the early Osagean Burlington Limestone of the United States midcontinent are reviewed. Burlington Barycrinus species include: B. rhombiferus (Owen and Shumard, 1852); B. magister (Hall, 1858); B. spurius (Hall, 1858); B. crassibrachiatus (Hall, 1860); B. scitulus (Meek and Worthen, 1860) n. combination; and B. sampsoni Miller and Gurley, 1896. Cyathocrinus latus Hall, 1861a, is here considered a junior synonym of B. rhombiferus. The stratigraphic practice of dividing the Burlington into upper and lower parts, for purposes of reporting species ranges, is evaluated.

Morphologic data from these Burlington species are combined with data from late Osagean and Meramecian botryocrinid species of Barycrinus and Meniscocrinus, plus four species of Devonian and Mississippian Costalocrinus in a parsimony-based phylogenetic analysis of Mississippian botryocrinids. Results of this analysis indicate that 1) species of Barycrinus form a monophyletic clade that radiated rapidly during the Osagean; 2) B. rhombiferus may have been ancestral to all other Barycrinus species; and 3) M. magnitubus forms a clade with the Mississippian C. cornutus (Owen and Shumard, 1850) and the Devonian C. rex McIntosh, 1984.

The late Albian marine fossil record from eastern Australia derives from the sedimentary succession of the Great Artesian Basin deposited in a vast epicontinental sea which then covered much of the continent (see Frakes et al., 1987). Ammonites of this age are common but their generic diversity is low. Heteromorph assemblages almost exclusively comprise the taxa Myloceras, Labeceras sensu stricto and Labeceras (Appurdiceras) of the Family Labeceratidae that were widely distributed in higher latitudes of the Southern Hemisphere during Late Albian time (see Aguirre Urreta and Riccardi, 1988; Klinger, 1989). Some 19 endemic species of these genera are recorded from the Great Artesian Basin in the present literature (Etheridge, 1892; Whitehouse, 1926; Reyment, 1964) and there are additional undescribed species (Henderson and McKenzie, unpublished data). The Australian Late Albian epicontinental sea was clearly a site of significant speciation for Labeceras and Myloceras and it has been argued that the Great Artesian Basin represents the evolutionary center for these genera (Henderson, 1990).

An extraordinarily well-preserved upper Homerian (uppermost Wenlock) post-extinction (post-lundgreni Event) graptolite fauna is described from Arctic Canada. The fauna of dendroids, retiolitids and monograptids, predominantly of uncompressed and isolated material, demonstrates almost totally new morphological features in comparison with the pre-extinction fauna. The two species of the lowest post-extinction fauna are followed by a rapid proliferation in the middle part of the interval, resulting in the maximum diversity, 21 species, for the entire upper Homerian. The upper Homerian is divided into three biostratigraphic units: the lower nassadubius Biozone, middle praedeubeli-deubeli Biozone, and the upper ludensis Biozone. The total fauna consists of ten species of monograptids and 11 species of retiolitids; of the latter group, three (Baculograptus, Papiliograptus and Doliograptus) are new genera, and six (B. batesi, P. papilio,P.? petilus,D. latus,Doliograptus sp. A, and Spinograptus praerobustus) are new species. Among the recognized species of monograptids, only Colonograptus schedidoneus and Lobograptus? cornuatus are confined to the Arctic, while five species of retiolitids (B. batesi,P.? petilus,D. latus,Doliograptus sp. A, and Spinograptus praerobustus) appear to be endemic.

The Lower Permian (Late Wolfcampian) marginal marine facies of the Robledo Mountains Member (Hueco Formation) of the Robledo Mountains, New Mexico, contains a diverse ichnofauna dominated by vertebrate trackways. Four new arthropod ichnotaxa are described. Tonganoxichnus robledoensis new ichnospecies, consists of repeated small traces comprising imprints of anteriorly directed legs, an elongate tapering abdomen, and a thin tail. Hedriumichnus apacheensis new ichnogenus and ichnospecies consists of isolated small traces comprising imprints of laterally-directed legs, a broad tapering abdomen, and a short tail. Rotterodichnium major new ichnospecies is a large trace with imprints of the head and thorax, a long thin abdomen and three pairs of legs, increasing in length posteriorly. Quadrispinichna parvia new ichnogenus and ichnospecies consists of four diverging or sub-parallel linear or curvilinear imprints of approximately equal length.

Tonganoxichnus, previously known from the Upper Carboniferous of eastern Kansas, is interpreted as produced by a jumping monuran (an extinct group of wingless insects). Hedriumichnus, known only from the Robledo Mountains, is interpreted as the resting trace of a nymph of a primitive Ephemeroptera or Plecoptera. Rotterodichnium, previously known from the Lower Permian of Germany, is interpreted as the resting trace of a large dragonfly-like form (Protodonata, Odonata, or Megasecoptera). Quadrispinichna, previously recorded but not named, from the Lower Permian Ecca succession of South Africa, is interpreted as a resting trace of a crustacean. These rare traces increase our understanding of the diversity and behavior of nonmarine arthropod communities in the Lower Permian.

A new collection of lagomorphs and rodents from the Deer Park B local fauna (l.f.) of Meade County, Kansas is described and compared with other small mammal assemblages of the Meade Basin, including the underlying Deer Park A l.f. Deer Park A was correctly assigned by Hibbard to the Blancan, bridging the gap between earlier Blancan faunas such as Fox Canyon and the late Blancan Sanders l.f. Recent fieldwork indicates that the Deer Park quarries may lie in the Rexroad Formation, rather than in the Ballard Formation as previously assumed. The geology and extinct mammalian contingent at Deer Park suggest that the lower horizon of Deer Park A was an active spring that gradually turned into a marshy environment during Deer Park B time. The rodents of Deer Park B are indicative of an open prairie ecosystem that might have been somewhat more arid than that of southwestern Kansas today.

This paper presents a phylogenetic analysis of the “Fallotaspidoidea,” a determination of the biogeographic origins of the eutrilobites, and an evaluation of the timing of the Cambrian radiation based on biogeographic evidence. Phylogenetic analysis incorporated 29 exoskeletal characters and 16 ingroup taxa. In the single most parsimonious tree the genus Fallotaspidella Repina, 1961, is the sister taxon of the sutured members of the Redlichiina Richter, 1932. Phylogenetic analysis is also used to determine the evolutionary relationships of two new species of “fallotaspidoids” distributed in the White-Inyo Range of California that have been previously illustrated but not described. These species had been referred to Fallotaspis Hupé, 1953, and used to define the occurrence of the eponymous Fallotaspis Zone in southwestern Laurentia. However, these two new species need to be reassigned to Archaeaspis Repina in Khomentovskii and Repina, 1965. They are described as Archaeaspis nelsoni and A. macropleuron. Their phylogenetic status suggests that the Fallotaspis Zone in southwestern Laurentia is not exactly analogous to the Fallotaspis Zone in Morocco, where that division was originally defined. Thus, changes to the biostratigraphy of the Early Cambrian of southwestern Laurentia may be in order. Furthermore, specimens of a new species referable to Nevadia Walcott, 1910, are recognized in strata traditionally treated as within the Fallotaspis Zone, which is held to underlie the Nevadella Zone, suggesting further biostratigraphic complexity within the basal Lower Cambrian of southwestern Laurentia.

Phylogenetic analyses of the Olenellina and Olenelloidea, along with the phylogenetic analysis presented here, are used to consider the biogeographic origins of the eutrilobites. The group appears to have originated in Siberia. Biogeographic patterns in trilobites, especially those relating to the split between the Olenellid and Redlichiid faunal provinces are important for determining the timing of the Cambrian radiation. Some authors have argued that there was a hidden radiation that significantly predated the Cambrian, whereas others have suggested that the radiation occurred right at the start of the Cambrian. The results from trilobite biogeography presented here support an early radiation. They are most compatible with the notion that there was a vicariance event relating to the origin of the redlichiinid trilobites, and thus the eponymous Redlichiid faunal province, from the “fallotaspidoids,” whose representatives were part of the Olenellid faunal province. This vicariance event, based on biogeographic patterns, is likely related to the breakup of Pannotia which occurred sometime between 600–550 Ma, suggesting that the initial episodes of trilobite cladogenesis occurred within that interval. As trilobites are relatively derived arthropods, this suggests that Númerous important episodes of metazoan cladogenesis precede both the earliest trilobitic part of the Early Cambrian, and indeed, even the Early Cambrian.

The Wilhelmi Formation of Illinois and the Mosalem Formation of Iowa contain monospecific assemblages of the stratigraphically important species Normalograptus parvulus Lapworth. This species is confined elsewhere to the uppermost Ordovician Normalograptus persculptus Biozone and the lower part of the lowermost Silurian Parakidograptus acuminatus Biozone. The presence of this graptolite raises the possibility that the lowermost parts of the Wilhelmi and Mosalem formations are of late Ordovician age rather than of early Silurian age as previously thought.

Representatives of the Prodromitidae are characterized by relatively large (up to 150 mm diameter) lenticular conchs with acute ventral keels and complex multilobate sutural configurations. The systematic position of the Prodromitidae has been the subject of considerable speculation (see Work et al., 1988 for review). The nominate genus, Prodromites Smith and Weller, 1901 (type species, Goniatites gorbyi Miller, 1891), is not typical and represents the culmination of the lineage, showing characters which have led authors to refer it to both the Gephuroceratina (Ruzhencev, 1960, 1962, 1965; Bogoslovsky, 1969; Ruzhencev and Bogoslovskaya, 1978) and the Prolecanitina (Miller and Collinson, 1951; Weyer, 1972; Furnish and Manger, 1973; Kullmann, 1981; Bartzsch and Weyer, 1988; Kullmann et al., 1991). Discovery of an ancestral prodromitid genus, Eoprodromites Work, Mapes, and Thompson, 1988 (type species, E. kinderhooki), in the Hannibal Shale of northeastern Missouri provided clarification on the derivation of Prodromites and provided a link to yet a third enigmatic genus, Qiannanites Ruan, 1981 (type species, Q. acutus). Work et al. (1988) concluded that the Prodromitidae were prolecanitid offshoots that appeared in the early Tournaisian with Qiannanites, progressed through Eoprodromites, and climaxed with Prodromites early in the late Tournaisian. Although aspects of sutural ontogenesis, conch morphology, and stratigraphic distribution unite these genera, subsequently obtained specimens of Eoprodromites kinderhooki provide additional sutural and morphological details (Figs. 1, 2) that support derivation from the prionoceratacean subfamily Pseudarietitinae Bartzsch and Weyer, 1987, as more recently suggested by Becker (1993a, p. 471).

One hundred and five sauropod tracks were excavated from black shale of the Uhangri Formation (upper Cretaceous), Haenam County, South Chulla Province, Korea. The tracks are true manus prints (not undertracks) and were made by sauropod dinosaurs while swimming.

Carbonaceous compression fossils in shales of the uppermost Doushantuo Formation (ca. 555-590 Ma) at Miaohe in the Yangtze Gorges area provide a rare Burgess-Shale-type taphonomic window on terminal Proterozoic biology. More than 100 macrofossil species have been described from Miaohe shales, but in an examination of published and new materials, we recognize only about twenty distinct taxa, including Aggregatosphaera miaoheensis new gen. and sp. Most of these fossils can be interpreted unambiguously as colonial prokaryotes or multicellular algae. Phylogenetically derived coenocytic green algae appear to be present, as do regularly bifurcating thalli comparable to red and brown algae. At least five species have been interpreted as metazoans by previous workers. Of these, Protoconites minor and Calyptrina striata most closely resemble animal remains; either or both could be the organic sheaths of cnidarian scyphopolyps, although an algal origin cannot be ruled out for P. minor. Despite exceptional preservation, the Miaohe assemblage contains no macroscopic fossils that can be interpreted with confidence as bilaterian animals. In combination with other late Neoproterozoic and Early Cambrian body fossils and trace fossils, the Doushantuo assemblage supports the view that body-plan diversification within bilaterian phyla was largely a Cambrian event.

Three new species of Viverravidae (Carnivora: Miacoidea) are described: Protictis simpsoni, P. minor, and Bryanictis paulus. Holotypes and referred specimens are from the Angel Peak area, Kutz Canyon, San Juan Basin, New Mexico and are of middle Torrejonian age (middle Paleocene). The holotype of Protictis simpsoni includes a skull—the oldest known skull of the Order Carnivora. The locality is narrowly restricted stratigraphically and geographically, and specimens are better preserved than most other viverravid specimens of San Juan Basin strata.