New rhynchonelliformean brachiopods are documented from Upper Cambrian and Tremadoc beds of the Cordillera Oriental and Puna regions, which are representative of the initial radiation of Plectorthoidea on the Andean (South American) shelves of Gondwana. Protorthisina n. gen., so far the oldest known representative of the family Euorthisinidae, and Lesserorthis n. gen. (Euorthisinidae?) are described, as well as the new species Euorthisina? nazarenensis, Kvania mergli, Kvania lariensis, Kvania azulpampensis (with two subspecies), Kvania? primigenia, and Nanorthis calderensis (with two subspecies). Protorthisina, Kvania, and Nanorthis form a stratigraphically continuous series of species displaying well-defined evolutionary trends involving size, shell ornament, and internal features. in the cardinalia, a transition from a V-shaped septalium (typical of Protorthisina) through almost parallel brachiophore plates (typical of Kvania) to the orthoid notothyrial platform of Nanorthis is documented. the species Nanorthis purmamarcaensis Benedetto and “Nanorthis” grandis (Harrington) are considered as the end members of the lineage. the heterochronic (peramorphic) origin of this trend is supported by ontogenetic evidence from species of Kvania and Nanorthis calderensis. the origin of the ‘plectorthoid’ cardinalia of Kvania from a euorthisinid configuration present in the stem group, followed by the appearance of a orthoidlike configuration in Nanorthis, pose an intricate systematic problem. the preliminary phylogenetic analysis of the northwestern basin taxa shows that the Upper Cambrian Protorthisina simplex n. gen. and sp. is the stem group of both the nanorthid and euorthisinid clades. On the basis of the new evidence, the genus Nanorthis is removed from the Orthoidea to the Plectorthoidea, and the diagnosis of the families Euorthisinidae and Nanorthidae are revised.

The ontogenies of three new species of Telephinidae, Telephina calandria, Telephina chingolo, and Telephina problematica are described from Arenig-Caradoc strata in the Argentine Precordillera, and compared with the larval stages of some other Proetida, including other telephinids.

New findings reveal 1) a radical metamorphosis in the ontogenies of these Telephina species late in the meraspid period, not previously described among Trilobita; and 2) distinctive hypostomes of Telephinidae containing long, thin anterolaterally and dorsally splayed anterior wings. Early ontogenies of different species currently assigned to the genus Telephina fall into at least two distinct morphological and life history groups, and hypostomes (if correctly assigned in previous works) vary significantly. The three new species strengthen the hypothesis of a phylogenetic connection between Oopsites and Telephina.

Three morphological types of protaspid instars are described for proetide trilobites. Two are anaprotaspides, and the third is a metaprotaspis. They always occur in the same sequence in the ontogeny, but no cases are known of all three types in the same species. These larval types are important for understanding the systematics and life cycles of the Proetida. Benthic/pelagic transitions identify four life history patterns among the the Proetida. The best larval synapomorphy for the Proetida is the distinctive metaprotaspid larval type, which is absent in very few proetides (some Telephinidae), perhaps as a result of heterochronic displacement of this stage into the meraspid period.

The Early Cambrian helicoplacoid echinoderms occur in the Cordilleran Geosyncline of western North America in strata correlated with the Atdabanian Stage of Siberia. Several higher taxa are recognized on the basis of inferred differences in the water vascular system, test organization, and external morphology. These are subclass Polyplacida Durham, with genus Polyplacus Durham; subclass Helicoplacida Durham and Caster, with n. family Helicoplacidae, type genus Helicoplacus Durham and Caster (with tubefeet emerging between two contemporaneous ambulacral plates); n. family Westgardellidae, with type n. genus Westgardella, type species H. curtisi (Durham and Caster) (with tubefeet emerging between two sequential ambulacral plates). The genus Waucobella Durham is also referred to Westgardellidae. Helicoplacus gilberti Durham and Caster, H. everndeni Durham, H. casteri n. sp., H. guthi n. sp., H. sp. a, and H. sp. b are assigned to Helicoplacidae. The genus Westgardella includes H. firbyi Durham, 1967, and W. blancoensis n. sp., in addition to the type species. No evidence of flooring plates separating the radial water vessel from the interior of the test is recognized. The mouth is at the top of the test in the interpretation adopted herein and not lateral as inferred by others; therefore, the ambulacral system is not triradiate. Illustration identified as Helicoplacus curtisi by Paul and Smith includes misidentified plates and should not be referred to this species.

Maurotarion Alberti, 1969, is a diverse otarionine clade that can be readily distinguished from Harpidella M'Coy, 1849. Both genera appear in the Upper Ordovician and range until the Middle Devonian. A new diagnosis for each taxon is given. New species of the genera from the Ordovician and Silurian of the central Mackenzie Mountains, Northwest Territories, Canada, include Harpidella kurrii (Ashgill), H. tikkaneni (Llandovery), H. greggi (Wenlock), and Maurotarion messieri (Llandovery). Harpidella megalops (M'Coy, 1846), H. triloba (Hu, 1975), H. spinafrons (Williams in Cooper and Williams, 1935), Maurotarion struszi (Chatterton, 1971), and M. instita (Whittington and Campbell, 1967) are revised.

Halkieriids are known largely from isolated sclerites, although it is understood that originally they formed the scleritomes of slug-like animals in Lower Cambrian benthic environments. The Yurtus Formation (?Tommotian–Atdabanian equivalent) of the Aksu-Wushi area, west Xinjiang, China, has yielded abundant sclerites. These are secondarily phosphatized, but show considerable detail. The sclerites can be divided into three classes: cultrates, long palmates, and short palmates; definite siculates have not been recognized. In some samples elongate to semicircular shells co-occur with the sclerites; these may derive from the same halkieriid scleritome. The external surface of the shells may bear a subdued ornamentation. The concave interior, however, is remarkable on account of a unique structure consisting of a group of nodular-like units. These may be arranged in a low cone or dispersed in a small circle. In addition to the sclerites of halkieriids and their possibly associated shells, rarer material is attributable to the related group of siphogonuchitids.

Nearly continuous cores from a 500-meter interval of upper Moscovian through post-Artinskian carbonate strata on the Finnmark Platform have yielded rich assemblages of fusulinaceans and smaller foraminifers. The fusulinaceans provide an independent time framework for evaluating stratigraphic occurrences of associated smaller foraminifers. Information derived from this study has been integrated with that from previous investigations to produce a smaller foraminiferal biostratigraphic model for the High Arctic. Kasimovian strata are characterized by occurrences of Nodosinelloides spp., Protonodosaria spp. and Hemigordius schlumbergeri. Overlying lower Gzhelian beds are identified by the appearances of Raphconilia modificata and Amphoratheca iniqua. Tezaquina clivuli and Cribrogenerina gigas first occur in upper Gzhelian strata, and Asselian rocks contain appearances of Geinitzina postcarbonica and Pachyphloia spp. Phylogenetic reconstructions suggest that the Late Carboniferous-Early Permian pseudovidalinids (Archaediscacea) derived from the Pseudoammidiscidae, as did the older group of predominantly Early Carboniferous archaediscaceans. The repeated development of similar morphologies within the two groups of archaediscaceans includes examples of both convergence and iterative evolution. The Protonodosariidae and Syzraniidae most likely evolved from an earlandiid ancestor. The syzraniids gave rise to the Geinitzinidae, which in turn gave rise to the Pachyphloiidae. As in the archaediscaceans, evolution within and among the Earlandiidae, Protonodosariidae, Syzraniidae, Geinitzinidae and Pachyphloiidae includes multiple examples of repeated patterns. Two key phenotypic developments seemingly led to bursts of diversification in different groups throughout late Paleozoic foraminiferal evolution. The acquisition of an outer hyaline or pseudofibrous wall layer was a morphologic breakthrough followed by taxonomic radiation in both groups of archaediscaceans and in the Earlandia-Syzrania lineage. The second major event was the shift from an undivided tubular morphology to uniserial morphology in both the Earlandiidae-Protonodosariidae and Syzraniidae-Geinitzinidae lines. Nodosinelloides pinardae is proposed as a new name for Nodosaria grandis Lipina, 1949 (preoccupied).

Shelly fossils from the basal Middle Cambrian, near the peak of Tizi n'Tichka in the central High Atlas, Morocco, include the new hyolithids Oboedalites peregrinus new species, Emarites decorissimus new genus and species, Patholites insolitus new genus and species, Rodentilites cricetus new genus and species, Slapylites afer new species, Tajinella mosei new genus and species, and Tizilites creber new genus and species. New orthothecid hyoliths are Gracilitheca destombesi new species, Contitheca chrosniaki new species, Sysoievia exilis new genus and species and an indeterminate species of Circotheca. The presence of Obeodalites, Slapylites, and Contitheca suggests a strong affinity to other Mediterranean and to Avalonian faunas. Their occurrence in Morocco extends their geographic ranges from Europe, and further reenforces their usefulness as indicators of Middle Cambrian age.

In this contribution, four species of Agathoxylon are described from the La Matilde Formation, Gran Bajo de San Julián and central and south-western sectors of Santa Cruz Province, Argentina. Agathoxylon agathioides (Kräusel and Jain) n. comb., Agathoxylon santalense (Sah and Jain) n. comb., Agathoxylon termieri (Attims) Gnaedinger and Herbst, and the new species Agathoxylon santacruzense n. sp. are described based on a detailed description of the secondary xylem. In this work, it was possible to construct scatter plots to elucidate the anatomical differences between the fossil species described on quantitative anatomical data. Comparisons are made with other Agathoxylon species from Gondwana. These parameters can be used to discriminate genera and species of wood found in the same formation, as well as to establish differences/similarities between other taxa described in other formations. Some localities contain innumerable “in situ” petrified trees, which allowed us to infer that these taxa formed small forests, or local forests, or small forests within a dense forest, which is a habitat coincident with the extant Araucariaceae.

The latest discovery of microfossils from the lower Cambrian (Fortunian Stage) Zhangjiagou Lagerstätte in South China are presented. This lagerstätte is rich in exceptionally preserved microfossils, including embryos of Olivooides multisulcatus, Olivooides mirabilis, and Pseudooides prima; hatched stages of O. multisulcatus, O. mirabilis, Hexaconularia sichuanensis, and Quadrapyrgites quadratacris; and cycloneuralians represented by Eopriapulites sphinx. The largest known fragment of O. mirabilis implies that its adult length can be more than 9.0 mm with at least 50 annuli, and the longest known specimen of Q. quadratacris has at least 18 annuli. These unusually large specimens refute the non-feeding larvae hypothesis for Olivooides and Quadrapyrgites.

Based on the current material, it is inferred that (1) early cnidarians have a high diversity in the Fortunian Stage; (2) P. prima might represent the embryonic stages of H. sichuanensis; (3) adults of Olivooides and Quadrapyrgites may have reached centimeter-scale dimensions with more than 50 annuli; (4) Olivooides and Quadrapyrgites may be better interpreted as coronate scyphozoans; (5) cycloneuralians also had a high diversity in the Zhangjiagou Lagerstätte; and (6) cycloneuralians might have originally been part of the early Cambrian meiofauna rather than belonging to the macrobenthos. Such ancestral cycloneuralians might have been Eopriapulites-like, possessing pentaradially symmetric, backward pointing, and internally hollow introvert scalids used as locomotory devices.

The fossil isopod crustacean genus Archaeoniscus has been known to occur in England, France and Germany during the Upper Jurassic, and in Mexico and Egypt during the Lower Cretaceous. The morphology of this genus is unique in having dorsoventrally compressed body, the cephalon set deeply into the first pereionite, pleon as wide as pereion, and a broad semicircular pleotelson. These features have resulted in placing the classification of the genus in the monotypic family Archaeoniscidae. However, due to the lack of detailed morphological data, suprafamilial classification of this genus has remained unclear, as well as its ecology and lifestyle. Here we report Archaeoniscus coreaensis n. sp. from the Jinju Formation, Gyeongsang Basin, Korea. The occurrence of Archaeoniscus in the East Asia implies that the genus may have had a worldwide distribution. The Gyeongsang Basin was a Cretaceous backarc basin, which consists of exclusively non-marine sedimentary sequences. The occurrence of this genus, therefore, indicates that Archaeoniscus successfully adapted to a freshwater ecosystem as well. Detailed anatomy including antennulae, antennae, pereiopods, and uropods was observed from well-preserved multiple specimens, which allows better understanding of the morphology of Archaeoniscus. The axial structure in the posterior part of the body, which was previously interpreted as a unique brood pouch characterizing the family, turned out to be a remnant of the hindgut. Females of all isopods and most of the members of the superorder Peracarida have a thoracic ventral brood pouch, modified from the thoracic coxal endites. Based on the morphology of the largely unmodified ambulatory pereiopods of A. coreaensis, the possibility of Archaeoniscus being ectoparasitic is discounted. Instead, the flattened body and the form of limbs of A. coreaensis would have been suitable for a benthic lifestyle.

The Moncure microvertebrate locality in the Cumnock Formation, Sanford sub-basin, North Carolina, dramatically increases the known Late Triassic age vertebrate assemblage from the Deep River Basin. The ∼50,000 recovered microvertebrate fossils include osteichthyans, amphibians, and numerous lepidosauromorph, archosauriform, and synapsid amniotes. Actinopterygian fossils consist of thousands of scales, teeth, skull, and lower jaw fragments, principally of redfieldiids and semionotids. Non-tetrapod sarcopterygians include the dipnoan Arganodus sp., the first record of lungfish in the Newark Supergroup. Temnospondyls are comparatively rare but the preserved centra, teeth, and skull fragments probably represent small (juvenile) metoposaurids. Two fragmentary teeth are assigned to the unusual reptile Colognathus obscurus (Case). Poorly preserved but intriguing records include acrodont and pleurodont jaw fragments tentatively assigned to lepidosaurs. Among the archosauriform teeth is a taxon distinct from R. callenderi that we assign to Revueltosaurus olseni new combination, a morphotype best assigned to cf. Galtonia, the first Newark Supergroup record of Crosbysaurus sp., and several other archosauriform tooth morphotypes, as well as grooved teeth assigned to the recently named species Uatchitodon schneideri. Synapsids represented by molariform teeth include both “traversodontids” assigned to aff. Boreogomphodon and the “dromatheriid” Microconodon. These records are biogeographically important, with many new records for the Cumnock Formation and/or the Newark Supergroup. In particular, Colognathus, Crosbysaurus, and Uatchitodon are known from basins of Adamanian age in the southwestern U.S.A. These new records include microvertebrate taxa more typical of non-Newark basins (abundant archosauriforms, temnospondyls, lungfish) as well as more typical Newark osteichthyans and synapsid-rich faunal elements.

Phylogeny is a succession of ontogenies, and the two have been compared by considering them in terms of rates of size change. In development, the larger the organism, the slower its rate of size increase. In evolution, the rates of size change can be put into three distinct categories: fast, medium, and slow. The fast changes occur over short periods of time (1–10 thousand years) and are as likely to show size decrease as increase. The medium changes occur over longer time spans (5–20 million years) and are predominantly or entirely instances of size increase. The slow changes occur over the entire span of organic evolution and represent the maximum size attained in various phyla, which again show an over-all increase.

For ontogeny, a decrease in rate of size change is correlated with an increase in complexity, an increase in the number of gene actions. For evolution, it is correlated with an increase in the number of genetic changes required of the genome by natural selection in fluctuating environments.

Alcidedorbignya inopinata Muizon and Marshall is a primitive pantodont from the Early Paleocene of Tiupampa, Department of Cochabamba, in the “Cordillera Oriental” of south-central Bolivia. It is known by almost complete upper and lower dentitions, which are described in detail. The occurrence of abundant juvenile specimens allows a study of tooth replacement. The molars of Alcidedorbignya inopinata are primitive for a pantodont but they show the characteristic synapomorphy of the group, which is the presence of a V-shaped ectoloph of P3-4. However, the paracone and the metacone of A. inopinata are separated at their bases, a feature absent in the Bemalambdidae and Harpyodus, which have connate to semi-connate paracone and metacone. Because of this character, A. inopinata, although the oldest, is not the most primitive pantodont. However, A. inopinata, as in bemalambdids and Harpyodus, does not have a mesostyle on M1-2/ or a strongly V-shaped centrocrista, which are found in all other pantodonts. For this reason, Alcidedorbignya inopinata is removed from the Pantolambdidae (which are too specialized) and referred to the new monotypic family Alcidedorbignyidae. The family Wangliidae Van Valen, 1988, is not accepted here and the genus Wanglia is regarded as a junior synonym of Harpyodus; the latter includes the two species H. euros and H. decorus. Analysis of pantodont origins leads to the conclusion that didelphodontines constitute the best potential sister-group; however, no synapomorphy could be found to substantiate this hypothesis. Alcidedorbignya inopinata is the first pantodont known from a southern continent and, being the oldest, it raises a discussion on the paleobiogeographic history of the group.

The skull of a carnivorous therapsid from the Tapinocephalus Assemblage Zone of the Beaufort Group, Middle Permian of South Africa, is described as a new burnetiamorph biarmosuchian. Pachydectes elsi n. gen. and sp. is distinguished from all other therapsids by its possession of a conspicuous pachyostotic maxillary boss that sheathes the root of the upper canine. It shares the presence of a preparietal ossification with other biarmosuchians and a pachyostotic boss below the postorbital bar with other burnetiamorphs. Pachydectes is the first burnetiamorph known from along the Ecca-Beaufort contact in the eastern part of the Karoo Basin and only the second burnetiamorph to be described from the Tapinocephalus Assemblage Zone. All other South African burnetiamorphs, save Bullacephalus jacksoni, are known from much younger biozones of the Beaufort Group. Our phylogenetic analysis links Pachydectes and Bullacephalus, which are the stratigraphically lowest-occurring taxa, with Burnetia, the burnetiamorph known from the highest position in the lower Beaufort Group. This result suggests that most of the history of biarmosuchians in South Africa is unrecorded.

In the dozen years since Alvarez et al. (1980) proposed their argument for dinosaur (and other) extinctions, lengthy debate has provided no consensus and the issue remains strongly polarized. The only test that has been proposed, that of additional fieldwork that sought to fill in the “gap” at the top of the Hell Creek Formation, recently has been conducted by Sheehan et al. (1991). Although the analysis found no indication of a gradual decline through the bulk of the formation, it did not produce the distribution Alvarez sought, a random distribution of remains clear through to the iridium. A second test based on the differing taphonomic predictions of catastrophic and noncatastrophic extinctions, and a comparison with the distribution of remains in the uppermost part of the formation, gives some credence to the latter and places considerable doubt on the former.

The Middle and Upper Ordovician sequence of the Langkawi Islands, northwestern peninsular Malaysia, contains 20 species of conodonts belonging to 15 genera and four unidentified species, which are described and illustrated. The following four biostratigraphic zones are established for the study area: the Scolopodus striatus assemblage zone, the Periodon sp. A range zone, the Baltoniodus alobatus range zone, and the Hamarodus europaeus range zone, in ascending order. The Middle Ordovician fauna belongs to the low-latitude, warm-water Australian Province. Conodonts of the H. europaeus zone represent the HDS (Hamarodus europaeus-Dapsilodus mutatus-Scabbardella altipes) biofacies, which has been reported from the cool-water North Atlantic Faunal Region. The middle Arenigian limestones in the study area were deposited on a shallow-water shelf, whereas the late Arenigian to middle Darriwilian limestones formed in hemipelagic deeper-water conditions on an outer shelf or slope.

The early Eocene green lacewings (Neuroptera, Chrysopidae) of the Okanagan Highlands deposits of McAbee, and Driftwood Canyon, British Columbia (Canada) and Republic, Washington (U.S.A.) are treated in detail for the first time. At least six genera are present, one unnamed, three new, with at least 10 new species, six named: Protochrysa fuscobasalis n. sp. (McAbee) (Limaiinae, the youngest known record of the subfamily), Okanaganochrysa coltsunae n. gen. n. sp. (McAbee), Adamsochrysa aspera n. gen. n. sp. (McAbee), A. wilsoni n. gen. n. sp. (Republic), Archaeochrysa profracta n. sp. (McAbee), and Pseudochrysopa harveyi n. gen. n. sp. (Driftwood Canyon) (all Nothochrysinae, the latter provisionally). The four unnamed species include one assigned to Pseudochrysopa, two likely belonging to Adamsochrysa, and one of an unknown nothochrysine genus. Microtholi are detected on the abdominal sclerites of Adamsochrysa wilsoni, and the spermatheca and spermathecal duct in the abdomen of Pseudochrysopa harveyi, the first reported occurrences of these preserved in fossil Chrysopidae. Structures were detected on the apical wing margins of some species that appear similar to trichosors, which are unknown in Chrysopidae, but are present in some other neuropteran families. This is the richest described assemblage of the family anywhere in the fossil record. Okanagan chrysopids were also morphologically and presumably ecologically diverse, including large species with rich venation and well as those with simplified venation and the smallest known fossil species. This is the oldest reported occurrence of the family in North America.

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.

Mixosaurus, a Middle Triassic ichthyopterygian, has traditionally been recognized as a typically primitive ichthyopterygian, but this view was recently questioned. Examination of the skull of Mixosaurus revealed many features to confirm this doubt. Its cranial characters, such as the parietal ridge and short supratemporal process of the parietal, are shared with derived ichthyopterygians from the Jurassic. Mixosaurus also has features that are derived within the Ichthyopterygia and unique to the genus, such as a long sagittal crest reaching the nasal, and an expanded anterior terrace of the upper temporal fenestra that also reaches the nasal. Phalarodon, Contectopalatus, and Sangiorgiosaurus are all considered as junior synonyms of Mixosaurus. The supratemporal, squamosal, and quadratojugal are all present in Mixosaurus atavus, as in basal ichthyopterygians. Because all basal ichthyopterygians, and even some derived ichthyopterygians from the Jurassic, have these three elements, the absence of the squamosal in Ichthyosaurus and Platypterygius should be considered derived if it is not preservational.

The Callovian Lagerstätte of La Voulte-sur-Rhône represents deep (bathyal) environments at the bottom of a submarine rocky slope. Three sea star body fossils partially replaced with pyrite were collected from clay beds. A small, stellate specimen is assigned to Terminaster cancriformis, a species already known from Jurassic clay deposits of Germany, Switzerland and England. the morphology of Terminaster illustrates mostly plesiomorphic features for post-Paleozoic sea stars, and the genus may be considered either as a paedomorphic Zoroasteridae or a stem group Forcipulatacea. Two specimens of a large multiarmed sea star are assigned to Decacuminaster n. gen. solaris n. sp., characterized by a lack of abactinal plates and an axial skeleton typical of the Velatida. the two genera Xandarodaster and Plesiastropecten are close to Decacuminaster and must be transferred to the Velatida. in modern oceans, the association of a multiarmed Velatida and a zoroasterid-like species would be typical of bathyal/abyssal environments, which suggests that these groups explored deep sea environments early in their history.