Paleozoic lagenide foraminifera are strikingly similar morphologically to Mesozoic and Cenozoic Lagenida, but because benthic foraminifers suffered a catastrophic reduction in diversity during the end-Permian mass extinction, it is unclear whether the similarities of Paleozoic lagenides and younger unquestioned Lagenida link them evolutionarily or are the product of convergence. Seven species representing five families of Paleozoic lagenide foraminifers were examined and found to possess mostly monolamellar hyaline-radial walls, as in extant nodosariid Lagenida. Exceptions are Protonodosaria rauserae Gerke, 1959, whose wall is not optically radial, and Syzrania amazonica Altiner and Savini, 1997, whose hyaline-radial wall may or may not be accompanied by a secreted inner microgranular layer. The inner microgranular layer is an element that is thought to have been inherited from the ancestral Fusulinida. Its absence in all but the earliest and morphologically simplest Paleozoic lagenides indicates more advanced wall structure than generally has been ascribed to this group. The wall in Pachyphloia spp. is secondarily thickened, suggesting plesio- or ortho-monolamellar construction, whereas other examined species exhibit atelo-monolamellar wall structure. These types of lamellarity are common among modern nodosariids. Thus, on the basis of not only morphologic similarity but also similar wall structure, we strongly suspect evolutionary continuity of lagenides across the Permian-Triassic boundary. The question is not completely resolved, however, because lagenides have not yet been recovered from lowest Triassic rocks.

Spicular radiolarians of the family Palaeoscenidiidae were recovered from the Llandovery to lower Wenlock of the Cape Phillips Formation, Nunavut, Canada. Several changes are made to the classification of these radiolarians. Goodbodium rarispinosum (Goodbody, 1986) was previously placed with Palaeoscenidium Deflandre, 1953. Insolitignum MacDonald, 1999 is emended to allow for additional apical rays. Insolitignum cancellatum (Goodbody, 1986) includes species which were previously assigned to Palaeoscenidium, Palaeotripus Goodbody, 1986, and Palaeoephippium Goodbody, 1986, owing to the variable development of one ray. Insolitignum peranima MacDonald, 1999 is synonymized with I. dissimile (Goodbody, 1986). Palaeodecaradium apertum (Goodbody, 1986) was previously placed with Palaeoscenidium; Palaeotripus nudus Goodbody, 1986 is considered a synonym of P. apertum. Palaeoephippium is rediagnosed based on the branching of the basal rays; the new diagnosis also allows for more than six rays and in orientations other than originally diagnosed. Palaeoephippium aranea Goodbody, 1986 is a junior synonym of P. bifurcum Goodbody, 1986. Palaeoephippium reteforme Goodbody, 1986 and P. ramipendentes Goodbody, 1986 are synonymized with P. radices Goodbody, 1986. Palaeotripus monospinosum Goodbody, 1986 is synonymized with Palaeoephippium spinosum Goodbody, 1986. One new species, Palaeodecaradium gordoni, is described. It possesses six rays; the apical rays are long and curved. The basal rays bear spinules on their lateral margins.

Four shell types are recognized from strophomenide brachiopods from Anticosti Island based on their fibrous or laminar character and on the type of taleolae. The shell types consistently co-vary with the types of cardinal process and style of socket plates. Treating shell structure as a conservative, non-reversing character implies that there are four groups of strophomenide brachiopod. The laminar-shell strophomenoids probably originated two separate times; one origination giving rise to two groups within the Strophomenida and one origination producing the Orthotetida. This matches the Treatise classification with only minor variation. The fourth group, that with fibrous shell and trilobed cardinal process and which includes the Plectambonitoidea, does not clearly fit into the Strophomenata and may be more closely related to the Clitambonitoidea. A limited cladistic analysis supports the idea that shell structure should be an important factor in establishing evolutionary kinship and points to ways of optimizing the Treatise classification.

Holorhynchus giganteus Kiaer, 1902, a common Late Ordovician (mid-Ashgill) pentameride brachiopod in the Baltic region, Kazakhstan, and southern Tien Shan, is documented for the first time from the Badanjilin Formation (mid-Ashgill) of western Inner Mongolia (Alxa block), North China. Serial sections of the Chinese material confirm the presence of a vestigial ventral median septum in the early growth stage of H. giganteus, but the septum becomes embedded in the secondary shell thickening at the adult growth stage. A survey of the type material from Norway and additional material from other regions indicates that the incipient ventral median septum is a much more commonly developed structure than was previously believed. The presence of a well-developed pseudodeltidium in the Tien Shan material of H. giganteus and the absence of such a structure in conspecific material from many other regions require a systematic revision of the generic group. Holorhynchus has rodlike crura (=brachial processes) that do not form flanges at their junctions with the inner hinge plates (=outer plates = crural plates) and outer hinge plates (inner plates). This, together with the development of a crude spondylial comb structure, points to its affinity to the Virgianidae rather than to the Stricklandiidae. Holorhynchus can be regarded as a Lazarus taxon because of its absence during the crisis (Hirnantian) and survival (early-middle Rhuddanian) intervals associated with the Late Ordovician mass extinction and its reappearance in Kazakhstan and North China during the Early Silurian (late Rhuddanian-early Aeronian). The mid-Ashgill Holorhynchus fauna, typified by a number of large-shelled pentamerides, was common in the Baltic region, the Urals, Kazakhstan, Tien Shan, Alxa, Qaidam, Kolyma, and east-central Alaska, but largely absent from Laurentia and Siberia (except for Taimyr) in the ancient tropical-subtropical regions. This paleobiogeographic pattern agrees with the general pattern of the Late Ordovician brachiopod provincialism.

The Middle Triassic bivalve genus Daonella Mojsisovics, 1874a has great potential for biostratigraphic correlation but a coherent systematic classification is still lacking. Many taxonomic characters previously used for Daonella classification depend on preservation and ontogeny, or intercorrelate strongly. The subgenus Daonella (Arzelella) Turculet, 1972 is revised on the basis of newly defined taxonomically significant characters and principle component analysis (PCA). Several species of this subgenus have been previously discriminated by characters taxonomically irrelevant such as the costae-free triangular fields adjacent the hinge (dependent on preservation), or they represent juvenile growth stages, which for instance show a more elongate shell form and no trifurcation of primary costae.

The use of this new systematic approach permits synonymy of many species with local distributions. The following species are considered as junior synonyms of D. (A.) tyrolensis Mojsisovics, 1874a: D. anastasiui Kittl, 1908; D. arzelensis Kittl, 1912; D. badiotica Mojsisovics, 1874a; D. loczyi Kittl, 1912; D. parthanensis (Schafhäutl, 1863) partim; D. cf. tyrolensis Kittl, 1912; and D. tripartita Kittl, 1912. Additionally, D. imperialis Kittl, 1912 is considered a junior synonym of D. (A.) taramellii Mojsisovics, 1874a. D. desecata (Schafhäutl, 1863) and D. frami Kittl, 1907 have been excluded from the subgenus Daonella (Arzelella). With knowledge of precise stratigraphic distribution in classical sections, a detailed supraregional biostratigraphic correlation becomes possible, in particular for the Southern Alps of Europe.

The Artinskian Metaperrinites and Kungurian Perrinites faunas are recognized from the Ratburi Group of the Loei area, northcentral Thailand, and the Saraburi Group of the Saraburi area, southcentral of the country, respectively. They represent one of the chains of the Asia-European perrinitid belt that was distributed within the ancient Tethys from Crimea in the west to Timor in the east. A total of 14 species representing 11 genera in the perrinitid faunas are illustrated and described herein.

Reevaluation of 21 specimens of Permian crustaceans from near Palermo, Italy, referred to Palaeopemphix Gemmellaro, 1890, has resulted in transfer of the genus from the decapod Crustacea to a new suborder, the Palaeopemphida, and a new superfamily, Palaeopemphidae, of the archaeostracan Phyllocarida.

The Shanglun Formation at the Shanglun locality contains a sinoleperditiine fauna of five species of which two are new [Sinoleperditia (Sinoleperditia) shanglunensis and Paramoelleritia (Paraleperditia) wangchengyuani] and one is left in open nomenclature because of inadequate materials. In this fauna, the ratio of the vertical height of the trailing chevron muscle scar to that of the adductor muscle scar (th:ah ratio) ranges from 0.85 to 0.95 with a mean value of 0.90. On the basis of the sinoleperditiines and a beyrichiid ostracode, the upper part of the Shanglun Formation is correlated with the middle-to-late early Emsian Moding Formation. The sinoleperditiines and microfacies analysis indicates that the sediments bearing the fauna were deposited in a low energy restricted carbonate platform environment.

All known post-Paleozoic asteroids belong to the crown group, and no crown-group asteroid is known from the Paleozoic. A scanty fossil record provides limited data on morphology of both Paleozoic stem-group sister lineages and on the Triassic crown group diversification. Timing of events is weakly constrained. Interpretations based on this meager record are tentative.

Within limitations of the record, recent work suggests that skeletal arrangement of the ventral surface offers apomorphies of crown-group diversification. Enlarged disk size is common in the crown group. Large disks are constructed in part by addition of many ventral and ventral-lateral so-called “actinal” ossicles. Actinals in the crown group are comparatively uniform in size, shape, and arrangement within each species. Actinal alignment is of one of two patterns, parallel to adambulacrals or parallel to marginals. Actinals in the crown group are tentatively considered to be an apomorphy of the crown group, although the incomplete fossil record leads to uncertainty.

Enlarged disks are found in some Paleozoic (stem-group) asteroids. Axillary ossicles, marginal series extending onto ventral interbrachia, and enlarged disk adambulacrals are modes of disk size increase known only from Paleozoic asteroids. Actinal ossicles are found in a few stem-group species but arrangements are unlike those of the crown group.

Certain Carboniferous and Permian genera share aspects of ambulacral column construction with the crown group, but lack actinal apomorphies. Actinal arrangement is available for two of the three known Triassic genera. In certain ways, patterns are intermediate between stem-group and Jurassic and younger crown-group asteroids.

The upper part of cores of the Onakawana B Drillhole in the Moose River Basin in northern Ontario includes the upper part of the upper member of the Williams Island Formation (22.5 m, 16 samples), and the entire overlying Long Rapids Formation (75.1 m, 49 samples). The sequence of conodonts from the drillhole was analyzed by graphic correlation as well as conventional zonation.

The upper carbonate member of the Williams Island Formation correlates with lower Frasnian zones 2 to 5. Below this, mixed Frasnian and Famennian conodont faunas occur partly in a brecciated interval within the member and represent stratigraphic leak below the Frasnian. The lower member of the Long Rapids Formation correlates in its lowest part with Zone 5, followed by a hiatus of zones 6 to 8. This is succeeded by zones 9 and 10. Zone 11 is missing, followed by an interval that correlates with upper Frasnian zones 12 and 13 to within the lower Famennian Middle triangularis Zone. The Frasnian-Famennian boundary occurs within a narrow interval in the lower member. The Upper triangularis Zone and perhaps part of the Middle triangularis Zone are missing.

The middle member of the Long Rapids Formation correlates with the Lower to Uppermost crepida zones. A sequence from high in the rhomboidea Zone to within the Lower marginifera to perhaps slightly into the Upper marginifera Zone occurs in the upper member of the formation.

Sixteen species are described, of which seven are new: Palmatolepis angularis, P. angusta, P. mystica, P. nodosa, P. parva, Palmatolepis n. sp. A, and Mehlina? unica. Two species that affect definition and identification of the Frasnian-Famennian boundary, P. triangularis and P. ultima (=P. praetriangularis), are revised.

The chimaeroid fishes enter the fossil record in the Triassic, multiply and diversify to at least 16 genera in the later Mesozoic (Stahl, 1999), and then dwindle during the Cenozoic to only six extant genera (Didier, 1995). Their origin and subsequent evolution have been difficult to trace because, like many other chondrichthyans, their remains consist most often of isolated teeth and fin spines freed and scattered after the cartilaginous skeleton disintegrated. Fossil species are commonly based on dental elements—tooth plates that were not shed like shark teeth but worn at the occlusal surface as they grew slowly from the base throughout life. The entire dentition is known from the extant taxa and from the few fossil specimens preserved with the head intact. It consists of a pair of mandibular tooth plates that occludes with two pairs of plates above, a large posterior palatine pair, and a smaller anterior vomerine pair (for dental terminology, see Stahl, 1999).

The late Neoproterozoic Doushantuo Formation in South China contains several exceptionally preserved biotas in its cherts, phosphorites, and black shales (Xiao et al., 1998b, 2002; Zhang et al., 1998). The three taphonomic windows—silicification, phosphatization, and carbonaceous compression—responsible for most of the preservation of nonbiomineralizing organisms in geologic history are all open in the Doushantuo Formation. In combination, these three taphonomic windows have the potential to give us a clearer and more complete picture of late Neoproterozoic biodiversity. Comparison across the three also allows us to evaluate possible taphonomic biases and paleoecological heterogeneity. To accomplish these, however, a more thorough paleontological investigation of each taphonomic facies is necessary.

Cheirolepidiaceous conifer pollen cones (Classostrobus arkansensis new species) from the Lower Cretaceous (Aptian/Albian) Holly Creek Formation of Arkansas, some still attached to Pseudofrenelopsis parceramosa Fontaine, shoots, bear helically arranged, semipeltate to dorsiventral microsporophylls with abaxially situated pollen masses. The in situ Classopollis Pflug, 1953 pollen and orbicule outer sculpturing consists of short spinules. The abaxial epidermis of the microsporophyll head consists of a stomatiferous central region of isodiametric cells bearing hollow papillae with rounded apices and a nonstomatiferous marginal area of elongate, nonpapillate cells. The head abaxial cuticles are thin relative to those of the shoot internodes. A cutinized hypodermis is lacking. Previously described pollen cones of Classostrobus comptonensis (Alvin et al., 1994) from the English Wealden (Barremian) are also associated with P. parceramosa shoots; however, they differ substantially from the Arkansas cones in possessing peltate microsporophylls with the abaxial surfaces bearing conical papillae, a cutinized hypodermis, and cuticles as thick as those of the shoot internodes. Therefore, at least two morphologically distinct pollen cones were produced on ultimate shoots conforming to P. parceramosa as presently circumscribed. Most cheirolepidiaceous conifers possess extremely thick cuticles on the abaxial surface of the microsporophyll head, which may suggest an unusual pollination biology entailing the production of fewer, relatively long-lived pollen cones. However, the thin cuticles and relatively abundant material of Classostrobus arkansensis n. sp. are more consistent with the typical coniferous pollination system, which includes production of numerous, ephemeral cones. Apparently, the Cheirolepidiaceae possessed a diversity of reproductive strategies.

Examples of the “hydrozoan” Radiotrabeculopora reticulata Fan, Rigby, and Zhang, 1991 have been recently recovered from Lower Permian rocks in the Inyo Mountains, Owens Valley area, of east-central California by G. Linder and C. Stevens. That genus and species were originally described from the Middle Permian (Leonardian-Lower Guadalupian) Maokou Formation from western Hubei, China, by Fan et al. (1991). This the first report of the genus and species from North America.

The bivalves of early late Anisian (Middle Triassic) age from Leidapo (also Bangtoupo) in the northeastern vicinity of Qingyan in the south-central part of Guizhou Province, southwestern China (Fig. 1), are highly diverse and fairly well studied (e.g., Chen et al., 1974; Yin, 1974; Nanjing Institute of Geology and Palaeontology, 1976; Gan and Yin, 1978; also Stiller, 2001). The study of these Anisian fossil assemblages began with Koken (1900) and Hsu and Chen (1943). The renewed study of this site and its fossil assemblages by Stiller (1997, 2001) and Chen et al. (2001) yielded a bivalve taxon with unusual and, for an early Mesozoic species, unexpected hinge features. The new taxon is fairly common at Leidapo/Bangtoupo; nevertheless it was only recently recognized (Stiller, 2001) and has not heretofore been described.

Kues and Batten (2001, p. 30, fig. 6.17–6.20) described several distinctive, minute, low-spired gastropod specimens from the Desmoinesian (Middle Pennsylvanian) Flechado Formation of north-central New Mexico, assigning them questionably to Lunulazona Sadlick and Nielsen, 1963 because of the strongly developed collabral elements similar to those of that genus. These shells, consisting of three or four inflated whorls, are at most 1 mm in height and the later whorls bear conspicuous, sharp, widely spaced collabral ribs that bend strongly across a wide, slightly flattened band interpreted as a peripheral selenizone. While recognizing these specimens as a distinct, unnamed taxon, Kues and Batten (2001) believed that they likely represent juveniles of an as yet unrecognized larger species of gastropod with a different mature morphology.

Studies of larval development in the calyptraeid gastropod genus Crepidula Lamarck, 1799 have greatly enhanced the ability of systematists to delineate the Recent species in this challenging group. Although the simple, limpetlike growth form and near absence of surface ornamentation in adult Crepidula provide few diagnostic characters, larval developmental strategies (i.e., feeding or planktotrophic vs. nonfeeding or lecithotrophic larvae) appear to be stable within species and evolve rapidly, making them useful taxonomic tools. Molecular phylogenetic analyses of several species previously believed to possess multiple developmental modes—a condition known as poecilogony—found that these “species” are instead clades comprised of multiple cryptic species distinguishable only by larval type (e.g., Gallardo, 1977, 1979; Hoagland, 1977, 1984, 1986; Collin, 2000a, 2001).