The Neoproterozoic Ediacara biota at Mistaken Point contains the oldest diverse Ediacaran assemblages and is one of the few known deepwater localities, yet the biota is dominated by endemic forms, nearly all of which remain undescribed. Thectardis avalonensis new genus and species, one of these endemic forms, is a cm-scale triangular fossil with a raised rim and a featureless-to-faintly-segmented central depression. More than 200 specimens occur on two bedding plane surfaces: the 565 Ma E surface and the 575 Ma Pigeon Cove surface, nearly 2,000 m lower in the succession. Morphological and taphonomic data suggest that the organism was an elongate cone that may have lived as a suspension-feeding “mat sticker” with its pointed base inserted into the microbially bound sediment. If true, Thectardis n. gen. would be the tallest-known mat sticker, reaching a maximum height of over 15 cm. Specimens display little ontogenetic change in length:width ratio, suggesting that Thectardis grew uniformly by incremental addition of material to its distal end. Morphological differences between specimens at two well-separated stratigraphic levels may have resulted from evolutionary or ecophenotypic variation.

New and previously described “Sphinctozoan” taxa have been collected from six different localities in northern Spain, all of them dated as Late Carboniferous, from Moskovian to Kasimovian in age. The sphinctozoans in the collection are all assigned to the Demospongiae: a new species of polyglomerate type, Cystothalamia vandegraaffi n. sp., and known species Amblysiphonella barroisi Steinmann, 1882, Amblysiphonella carbonaria (Steinmann, 1882), Discosiphonella mammilosa (King, 1943), Discosiphonella maior (Van de Graaff, 1969), and Sollasia ostiolata Steinmann, 1882. Some of these specimens present interesting paleoecological features, such as the use of a piece of calcareous algae as a hard substrate in a soft muddy bottom and a possible branching pattern determined by photophilic or negative geotaxic growth.

Detailed analysis of certain growth characteristics in Trabeculites maculatus contributes to an understanding of the paleobiology and phylogeny of early tabulate corals. Some coralla of T. maculatus contain peculiar, vertically oriented cylindrical lacunae (open areas) that are lenticular, or in one case circular, in cross section. The nature of these structures and their relation to adjacent corallites suggest that they were formed by the coral in response to soft-bodied biotic associates of unknown taxonomic affinity.

Trabeculites maculatus is an unusual tabulate coral featuring both axial and lateral modes of corallite increase. Axial increase was common, often occurring in association with rejuvenation following injury and less commonly involving normal, undamaged corallites. Lateral increase of normal corallites was typical, but this form of increase could also be involved in the termination of lacunae and occurred in response to a divergent growth pattern around the circular lacuna. Corallite decrease was fairly common, usually taking place adjacent to lenticular lacunae but in some cases involving normal corallites not associated with lacunae. Corallite fusion was uncommon; it could be either temporary or permanent. Conspicuous relocation of corallites and restructuring of corallite arrangement generally involved mass rejuvenation and/or regeneration, usually over a large surface area of the corallum.

The growth features in T. maculatus are fundamentally the same as those in the co-occurring Saffordophyllum newcombae, including types of axial increase unknown in other tabulate corals. The basic paleobiologic similarity of these species supports the interpretation that the genera they represent are closely related phylogenetically. The relationship of these taxa to other tabulates, however, remains unresolved.

A previously unknown Namurian goniatite and brachiopod fauna is described from Southeast Asia. The goniatites provide new insights into their global distribution and the age of the fauna. Two new brachiopod genera, Eileenella Racheboeuf and Plicambocoelia Boucot and Brunton, and five new species are described. The brachiopod fauna is unlike any known previously from Asia.

Based on well-preserved material from the Sinemurian of the western Carpathians, the new subgenus Terquemia (Dentiterquemia) is proposed, which is presently represented only by its type species T. (Dentiterquemia) eudesdeslongchampsi n. sp. Dentiterquemia is separated from Terquemia sensu stricto by a series of denticles along the hinge margin and corresponding, chevronlike ridges on the ligament area. The combination of hinge teeth with a cementing habit is interpreted as a defense strategy inhibiting torsion of the valves as well as manipulation of the animal as a whole. Whereas different kinds of articulating hinge structures evolved independently in several clades of early Mesozoic cementing bivalves, Paleozoic cementing bivalves generally lack such structures. It is proposed that this difference reflects an early Mesozoic proliferation of durophagous predators and therefore points to a beginning of the “Mesozoic marine revolution” soon after the end-Permian mass extinction.

Many bivalves and brachiopods possess multilayered shells. In one such bivalve, Mytiloides ipuanus (Wellman, 1959) (Inoceramidae), the mineralized shell comprises an outer prismatic calcite layer and an inner nacreous aragonite layer. Each of the three shell surfaces—the external, internal, and shell layers' interface—has a distinct sculpture. Pronounced costae on the shell interface are “cryptic” in the sense that, in life, they would have been barely expressed on the internal surface and only expressed as comparatively weak, broad, rounded costae on the external surface. In fossil specimens, depending on the timing of shell dissolution relative to compaction and lithification, any of these sculptures may be preserved and combined in various ways on simple or composite surfaces/molds. Many of the resulting specimens appear to be morphologically quite distinct from each other. The form and distribution of particular “taphomorphs,” however, can be predicted from a knowledge of shell mineralogy and taphofacies. The different sculptures present on the three shell surfaces, and their wide range of taphonomic expressions, had not been recognized previously, resulting in the erection of three nominal taxa for this single species, based on different taphomorphs. It is not clear whether similar problems remain undetected in other multi-shell-layered invertebrate fossil groups.

Pectinids are the most abundant and widely distributed taxa in the Tertiary marine beds of Patagonia. Along with other very common molluscan species, they characterize five assemblages, from oldest to youngest: 1) the Oligocene Panopea sierrana-Parinomya patagonensis Assemblage; 2) the Late Oligocene–Early Miocene Jorgechlamys centralis–Reticulochlamys borjasensis Assemblage; 3) the Early Miocene Reticulochlamys zinsmeisteri–Struthiolarella patagoniensis–Pleuromeris cruzensis Assemblage; 4) the Early Miocene Pseudoportlandia glabra–Antimelatoma quemadensis Assemblage; and 5) the latest Early Miocene–earliest Middle Miocene Nodipecten sp.–Venericor abasolensis–Glycymerita camaronesia Assemblage. A brief analysis of the origin and composition of these Tertiary Patagonian molluscan faunas is provided. Striking compositional changes occurred through time, recorded mainly in the Late Paleocene, Late Eocene, Late Oligocene–Early Miocene, and Late Miocene.

Mexfusus rotundicostatus new genus and species is a neogastropod of uncertain affinities from the Late Cretaceous (Early Maastrichtian) Mexcala Formation of southern Mexico. It is characterized by strong, rounded, axial ribs, fine spinelets at the intersection of axial ribs and sharp spiral cords, subsutural cord, strong simple spiral cords, and an apparently smooth, glazed columellar lip. A possible second species is Peristernia conica Riedel, 1932 from the Coniacian of Cameroon.

The Mississippian ammonoids Polaricyclus conkini new species, P. ballardensis (Gordon, 1965), Winchelloceras knappi new species, and Cantabricanites? greenei (S. A. Miller, 1892) occur with Gnathodus texanus Zone conodonts near the base of the New Providence Shale Member of the Borden Formation in north-central Kentucky. Both ammonoids and conodonts indicate an early late Osagean (lower Keokuk equivalent) age corresponding to the middle or, more probably, the late Chadian (latest Tournaisian or early Viséan) portion of the Fascipericyclus–Ammonellipsites Zone.

The discovery of a new naraoiid nektaspid in the Upper Silurian (Pridolian) of southeastern Ontario significantly extends the range of this unusual group. Nektaspids are nonmineralized arthropods typical of Early and Middle Cambrian soft-bottom communities, but were thought to have become extinct in the Late Ordovician. The unique holotype specimen of Naraoia bertiensis n. sp. comes from a Konservat–Lagerstätte deposit renowned for its eurypterid fauna (the Williamsville Member of the Bertie Formation). Naraoia bertiensis lacks thoracic segments and is morphologically similar to Naraoia compacta from the Middle Cambrian Burgess Shale, save for the presence of a long ventral cephalic doublure and a subtly pointed posterior shield. To examine the phylogenetic relationships of the new naraoiid, we coded characters of the holotype specimen and of nine previously described nektaspids. The results confirm a sister taxon relationship between Naraoia compacta and Naraoia bertiensis and the monophyly of nektaspid forms lacking thoracic segments (family Naraoiidae). This latter group may have arisen from an ancestral segment-bearing form through heterochronic loss of thoracic segments early in the Cambrian. The disjunct occurrence of a naraoiid nektaspid in the Late Silurian resembles the reappearance of other “Lazarus taxa” that were thought to have been eliminated during mass extinction events. The naraoiid lineage survived the Late Ordovician biotic crisis, but in this case the “Lazarus effect” seems likely to be taphonomic in origin.

Despite their importance in breaking down lignified tissue today, much is still unknown about the role of mites in the fossil record, especially with reference to the Paleozoic–Mesozoic transition. This study examines permineralized peat from three localities in the central Transantarctic Mountains, ranging in age from Permian to Jurassic, for evidence of diversity and abundance of wood-boring mites. Evidence of mites, in the form of coprolites and tunnels in wood and other tissues, was found at all three localities; the Triassic site included more than 10 times as many wood borings as the Permian site. Our results supplement prior evidence of wood-boring mites during the Mesozoic and thereby fill in the known geologic range of this plant/animal interaction.

We characterized the skeletal crystallography of representatives of nine rhombiferan, three diploporan, and three paracrinoid species. Crystallographic data from these groups are similar to data from previous studies of crinoids, echinoids, and blastoids in that 1) orientations of c axes are consistent within species and within higher taxonomic groups; 2) c axes typically are oriented subparallel to the medial plane of their respective plates; and 3) the inclination of axes within the medial plane varies between taxa. Rhombiferan c axes are oriented normal to plate surfaces whereas diploporan c axes are tangential to plate surfaces. Paracrinoids more closely resemble diploporans in having irregular patterns of thecal plating but their c axes are approximately perpendicular to plate surfaces as in rhombiferans.

In contrast to c axes, a axes in all specimens show little regularity and cannot be distinguished from random orientations.

The rhombiferan Caryocrinites ornatus displays minor differences in the inclinations of c axes depending on the location of skeletal elements on the theca. Plates at the base of the theca have slightly aborally inclined axes, whereas distal plates have axes inclined slightly adorally. This pattern matches orientations in some early crinoids, suggesting similarities between rhombiferans and crinoids in development or skeletal construction.

Skeletal crystallography in various echinoderms can be compared in light of hypotheses of homology proposed in the Extraxial-Axial Theory (EAT). Skeletal elements homologized under the EAT do not correspond to any particular crystallographic axis orientation, suggesting that the homologies proposed in the EAT encompass significant underlying skeletal variation.

Remains of a large sea turtle, Terlinguachelys fischbecki n. gen. and sp., were recovered from paralic deposits of the Upper Cretaceous (Campanian) Aguja Formation in Big Bend National Park, Texas. T. fischbecki is a primitive protostegid that retains a constricted humerus, well ossified plastron and costals, prominent retroarticular process on the lower jaw, and long slender femora; however, it has some features, such as a prominent tubercle at the base of the scapular acromion process, found elsewhere only in derived leatherback sea turtles. The unique combination of primitive and derived traits in T. fischbecki illustrates further diversity among Cretaceous sea turtles and another case of parallelism common in sea turtle phylogeny.

The Antilocapridae was a diverse artiodactyl family present in some late Tertiary faunas of North America. In México, its Tertiary fossil record is poorly known. The antilocaprid material described in this paper was collected from the early Blancan fluvial deposits of the San Miguel de Allende Area, state of Guanajuato, México. It includes isolated upper and lower premolars and molars, dental series, and some rami fragments. The material is assigned to Capromeryx tauntonensis. The presence of this species in the early Pliocene of central México represents the oldest record in North America and extends its known geographic distribution from the northwestern United States to central México.

The lower Cretaceous strata of the Neuquén Basin of Argentina are richly fossiliferous and characterized by diverse, primarily normal marine, molluscan-dominated faunas containing many interesting taxa. Among these, in the Lower Hauterivian part of the Agrio Formation at Cerro Mesa (Fig. 1), are diverse, coarsely ornate trigoniid bivalves of the genus Steinmanella Crickmay, 1930, and a new genus and species of ornate Mytilidae (Nodomytilus trigonimimus). The new taxon appears to be convergent in its surface sculpture on the Austral Gondwanian trigoniid Steinmanella transitoria (Steinmann, 1881). This may represent a rare case of convergence, or even mimicry, in the fossil record. The trigoniids have relatively low predation levels among bivalves (Kauffman, personal observation on fossil and recent populations). Convergence on the trigoniid morphotype could have been an adaptive advantage to frequently predated Mytilidae. The new taxon is described herein and compared to co-occurring Steinmanella.

The stephanid wasps are of great phylogenetic and biological significance among parasitic Hymenoptera, itself one of the major radiations of insects and of critical ecological and agricultural importance. The family, the only one of its superfamily (e.g., Gauld and Bolton, 1988; Goulet and Huber, 1993: although Rasnitsyn, 1988, 2000 includes the traditional Trigonalyoidea, Megalyroidea, Ceraphronoidea, and some extinct lineages in the Stephanoidea), is hypothesized by some authors to be basal within the diverse parasitoid lineage Apocrita (Rasnitsyn, 1975, 2000; Königsmann, 1978; Rohdendorf and Rasnitsyn, 1980; Whitfield, 1992, 1998; Vilhelmsen, 1996, 2001). Such a phylogenetic placement makes the stephanids an interesting link between the principally xylophagous wood wasps (i.e., the paraphyletic suborder Symphyta), the sole parasitic symphytan family Orussidae, and the remainder of the Apocrita (Orussidae + Apocrita = Euhymenoptera). Thus, stephanids may represent one of the earliest families of parasitoid wasps exhibiting the characteristic “wasp waist,” allowing for more control and flexibility during oviposition. Tantalizingly, the stephanids are morphologically similar to orussids in that both exhibit a characteristic series of tubercles on the head (presumably an adaptation for allowing them to move through burrows in wood after eclosion). These similarities, however, may be convergent adaptations of parasitizing wood-boring insects (a plesiomorphic biological trait across the Apocrita) and stephanids may belong to a clade of evaniomorphous wasps, albeit still relatively basal within that lineage (e.g., Rasnitsyn, 1988; Ronquist et al., 1999). In either case, Stephanidae figure prominently in cladistic studies of the Hymenoptera and are of presumably ancient origin based on their phylogenetic position (e.g., Rasnitsyn, 2000). Fossils of the family, however, are rare and until now have been restricted to Tertiary deposits.

Bittacidae is small family of insects, but a major family of mecopterans, with about half of its genera known from the Mesozoic (Handlirsch, 1939; Sukatsheva, 1990; Novokschonov, 1993, 1997a, 1997b; Ren, 1993, 1997; Ansorge, 1996; Petrulevičius and Martins-Neto, 2001), mainly from the Jurassic. Cenozoic records are scarce and in most cases are assigned to extant genera (Jarzembowski, 1980; Novokschonov, 1993; Petrulevičius, 1998, 1999, 2001a, 2001b).

The goliath grouper (family Serranidae, subfamily Epinephelinae) inhabits tropical and subtropical waters. The Epinephelinae serranids are comprised of about 159 species in 15 genera (Heemstra and Randall, 1993) and are represented in all oceans. According to Heemstra and Randall (1993) the goliath grouper Epinephelus itajara (Lichtenstein, 1822) occurs in the eastern Atlantic Ocean from Florida to Brazil, throughout the Gulf of Mexico and in the Caribbean Sea, in the western Atlantic Ocean from Senegal to the Congo, and in the eastern Pacific Ocean from the Gulf of California to Peru. The maximum size is about 250 cm total length and they can exceed 320 kg in weight. The grouper Epinephelus lanceolatus (Bloch, 1790) occurs throughout the Indo-Pacific region, from the Red Sea to Algoa Bay, South Africa, and eastward to the Hawaiian and Pitcairn Islands, and in the western Pacific Ocean from southern Japan to Australia in the south. The maximum size is about 231 cm total length (Schultz, 1966) and 400 kg in weight (Fourmanoir and Laboute, 1976). These two species are the largest serranids in the world. Sadovy and Eklund (1999) noted that males reach a maximum age of 26 and females 37 years in a population of E. itajara.

Dispersed megaspores with affinities to aquatic heterosporous ferns are relatively common in mesofossil assemblages from the Early Cretaceous to the Recent. Extant heterosporous ferns are free floating or shallow rooted freshwater plants, with a dominantly tropical to warm-temperate distribution (Tryon and Lugardon, 1991). Their heterosporous life cycle (including both megaspores and microspores) is likely to be an adaptation to their aquatic habit (Collinson, 1991; Hemsley et al., 1999; Kar and Dilcher, 2002). Thus the abundance of heterosporous fern megaspores, or the presence of heterosporous fern macrofossils, within a stratigraphic interval may be indicative of a shallow, calm, freshwater depositional environment (Hall, 1963; Batten et al., 1996; Rich et al., 2001).

A unique specimen of the micromorphic fossil lingulate (organophosphatic-shelled) brachiopod Linnarssonia constans Koneva, 1983 from the late Lower Cambrian Shabakty Group of the Malyi Karatau Range in Kazakhstan, Central Asia, preserves evidence of infestation within the mantle cavity by a vermiform animal, leading to the growth of an internal tubular protuberance (Fig. 1) resulting from symbiosis some 520 million years ago. Examples of symbiotic relationships between metazoans in the early Paleozoic are sparse (Conway Morris, 1981, 1990; Conway Morris and Crompton, 1982). Descriptions of a variety of galls and tumorlike swellings in some trilobites extend records back to the Middle Cambrian (Conway Morris, 1990), but their interpretation as traces of endoparasitic activity remains somewhat speculative. Thus galllike swellings on the stems of Silurian echinoderms (Franzen, 1974), vermiform tubes on some early Ordovician dendroid graptolites (Conway Morris, 1990), and various tubes and blisters on graptoloid graptolites (see Bates and Loydell, 2000 for review) are among the hitherto earliest known convincing records of host-parasite relationships within metazoans. Our example reported here predates the oldest of these previous records by approximately 35 to 40 million years, and demonstrates that symbiosis involving complex adaptations (e.g., larval settlement on or within living tissue and exploitation of feeding systems of the host) and codependent life cycles were already established soon after the ‘explosive’ evolutionary radiation of marine metazoans in the early Cambrian. The fossil evidence of infestation on lophophorates is especially sparse, at best. The oldest hitherto undoubted records are both from brachiopods of Devonian age, in the Lower Devonian Emsian Stage of eastern Australia and in the Middle Devonian Givetian Stage of the Holy Cross Mountains in Poland, respectively.