Specimens of the ammonite genus Balatonites from the Middle Triassic of Austria and Hungary are analyzed morphometrically to obtain growth invariant character states. A new method transforming growth dependent qualitative characters into age invariant metric variables is developed. Weighted standardization as a method preserving univariate discriminatory efficiency is applied to character states preceding numerical classification procedures, resulting in a clearer separation of homogeneous groups in comparison to simple standardized data. All clustering and ordination procedures produce two identical classes, which are interpreted according to the cohesion concept as distinct biological species. In adherence to the taxonomic rules they are denominated as Balatonites egregius Arthaber and Balatonites balatonicus (Mojsisovics).

A new fossil species of Dermestidae (Insecta: Coleoptera), preserved in Late Cretaceous (Turonian) amber from New Jersey, is described as Attagenus (Aethriostoma) turonianensis n. sp. The specimen is fossilized in translucent amber, but 3D imaging using propagation phase-contrast X-ray synchrotron microtomography allowed detailed classification and description. This species is the oldest representative of the subfamily Attageninae and the third fossil species described in the family from the entire Mesozoic. Dermestidae comprise beetle species that typically feed on carcasses, although some Recent species of Attagenus Latreille, 1802 are known to feed on plant debris, which is highly abundant in amber deposit sediments. This new species is evidence for diversification in the family during the Early Cretaceous as well as long morphological conservation of diagnostic features of the genus Attagenus from the Late Cretaceous. Analyzing the taxa from Mesozoic ambers that show stasis, the small size of the specimens together with a specific ecology could explain the stability of these lineages.

Cladistic analysis of the trilobite subfamily Acanthoparyphinae Whittington and Evitt, 1954, yields an explicit hypothesis of relationship for the group. All Silurian species together form a robustly supported monophylum including the genera Hyrokybe Lane, 1972, Parayoungia Chatterton and Perry, 1984, and Youngia Lindström, 1885. Sister to this is the Ordovician type species of Acanthoparypha Whittington and Evitt, 1954. Remaining species that have historically been assigned to either Acanthoparypha or Pandaspinapyga Esker and Levin, 1964, form a rather labile paraphylum. Nevertheless, the entire group thus identified is definitely monophyletic, and supported by several prominent synapomorphic character-states.

The basal structure and basal node of the subfamily are more difficult to assess. The relationships of the genera Hammannopyge Přibyl, Vaněk, and Pek, 1985, Holia Bradley, 1930, and Nieszkowskia Schmidt, 1881, need to be addressed within the wider context of the family as a whole. The traditional assignment of Holia to the acanthoparyphines is followed.

Wenlock acanthoparyphines from the Cape Phillips Formation of the central Canadian Arctic islands include several species of Hyrokybe and Parayoungia. They are similar to, and in one case conspecific with, coeval forms to the southwest in the southern Mackenzie Mountains.

Five species are new: Holia glabra, Hyrokybe lightfooti, Hyrokybe youngi, Hyrokybe mitchellae, and Parayoungia mclaughlini. At least four other potentially new species are reported in open nomenclature.

A new dataset of the highest quality specimens of fully articulated, juvenile and mature exoskeletons of the Czech middle Silurian trilobite Aulacopleura koninckii offers improved resolution of original morphology by all measures considered. The degree of variation in both size and shape among later meraspid instars was constant, and suggesting targeted growth in both attributes. Size-related changes in the shape of the dorsal exoskeleton and of the segment-invariant cephalon were detected in the meraspid stage, but in the holaspid phase marked allometry was detected only in the trunk region, with the pygidium showing notable expansion in relative size. Meraspid cranidial allometry was subtle, with significant changes in instar form detectable only after several molts. This trilobite developed gradually throughout meraspid and holaspid ontogeny, with the synchronous cessation of trunk segment appearance and release at the onset of the holaspid phase. Precise development of shape and size occurs in the context of marked variability in the number of trunk segments at maturity, illustrating complex patterns of character variation within a species. A new systematic description establishes the synonymy of several subspecies with A. koninckii.

The Pennsylvanian fusulinid genus Profusulinella appeared in sub-Arctic North America in Medial Atokan (=Early Moscovian) time, roughly 4–5 My later than its oldest known occurrence in the Eurasian-Arctic province. the genus originated in the latter area in late Early Bashkirian time and then underwent significant diversification, so that by Early Moscovian time a range of shell morphologies existed. the first sub-Arctic North American species in the genus are interpreted as immigrants from Eurasia, with their migration through the Franklinian corridor having been facilitated by generally east-to-west currents during a glacio-eustatic flooding event. Previous work suggested that North American Profusulinella spp. may have derived from a local ancestor such as Eoschubertella. This possibility seems unlikely given that early North American species in Profusulinella are very similar to age-equivalent Eurasian forms, that they differ from North American Eoschubertella in a number of morphologic features, and that there are no known North American intermediates between Eoschubertella and Profusulinella. Fusulinoidean faunas apparently migrated from Eurasia to North America on multiple occasions during Pennsylvanian time. These migrations were an important source of North American diversity, and their recurrence is a dominant theme in fusulinoidean biogeography.

A diverse assemblage of Middle Cambrian sponges, recently collected from the Wheeler and Marjum Formations of western Millard County, Utah, includes a variety of demosponges and hexactinellids. This collection includes the verongiid Vauxia bellula Walcott, 1920, and the protomonaxonids Choia carteri and Choia ridleyi Walcott, 1920, Hamptonia bowerbanki Walcott, 1920, and Hamptonia parva n. sp. Hexactinellids in the collection include the reticulosid protospongioids Diagoniella hindei Walcott, 1920, and Diagoniella magna n. sp.; the dierespongioid hydnodictyid Valospongia? gigantus Rigby, 1973; and the hintzespongioid Hintzespongia bilamina Rigby and Gutschick, 1976. A specimen of the problematic Sentinelia? draco Walcott, 1920, is also documented as part of the collection.

Most species of the genus Pliosaurus Owen, 1842 come from the Northern Hemisphere, however, a growing number of new specimens are now available from the Southern Hemisphere. Here, a new species of Pliosaurus is described, the second for the genus from the Southern Hemisphere, collected from the upper Tithonian (Jurassic) levels of the Vaca Muerta Formation, Neuquén Province, Patagonia. Pliosaurus almanzaensis new species is characterized by two autapomophies: the angular participating in the mandibular symphysis and the occipital condyle without a notochordal pit or several, irregularly arranged grooves. Additionally, P. almanzaensis n. sp. can be differentiated from other Pliosaurus species by the following characters: trihedral teeth, nine or more symphyseal alveoli, 15–17 post-symphyseal alveoli, and the parasphenoid without a ventral keel. Pliosaurus almanzaensis n. sp. shows that Pliosaurus species with nine or more symphyseal alveoli persisted until the late Tithonian, contrary to previous assumptions that only species with six symphyseal alveoli were present.

Previously described upper and lower molars from the Fort Union Formation (Swain Quarry, Wyoming) are referred to Swaindelphys cifellii new genus and species. This taxon is assigned to the subfamily Herpetotheriinae, family Didelphidae. These molars were originally referred to a new, unnamed species of Peradectes (subfamily Peradectinae), with similarities to P. pusillus (now Thylacodon pusillus) and P. elegans. However, upper molars differ from these taxa in being dilambdodont, in possessing more strongly developed stylar cusps, especially on M2 and M3, and in having a protocone that is shifted anteriorly. These characters suggest similarity to taxa such as Peratherium (subfamily Herpetotheriinae, family Didelphidae), rather than Peradectes. The assignment of the lower molars from Swain Quarry is more problematic: these molars are similar to the holotype Thylacodon pusillus in that the entoconid and hypoconulid separated by a strong notch; however, the Swain Quarry lower molars differ in being smaller overall and possessing an anteroposteriorly shorter talonid. These lower molars are similar to didelphid lower molars in having a hypoconulid that is lower than the entoconid (these are subequal in height on lower molars of Peradectes), but differ from didelphid lower molars in that the hypoconulid does not form a low, posteriorly projecting shelf. Nevertheless, the upper and lower molars from Swain Quarry are considered to belong to a single taxon, and with the assignment of the Swain Quarry materials to the subfamily Herpetotheriinae, the geological range of this subfamily is extended from the early Eocene back into the middle Paleocene (Torrejonian, or To3).

The recovery of well-preserved silicified immature exuviae allows the first description of the early ontogeny of the phacopid Nephranops incisus incisus from the lower Famennian of Thuringia (central Germany). Evidence is presented that both planktonic and benthic protaspid larval stages were present in phacopid trilobites. Ontogenetic meraspid changes of this species are similar to those of Weyerites and Phacops, supporting the close phyletic relationships between these genera and the ontogenetic homogeneity of the Phacopidae.

Considerable systematic work devoted to late Cambrian trilobites includes very little species-level phylogenetic analysis. This paper presents the phylogenetic analysis of 36 species representing eight genera assigned to the Family Pterocephaliidae that occur in the Great Basin of the western United States during the Steptoean stage (Furongian). Continuous characters are treated in four different ways: discretization using finite mixture coding, discretization using gap-weighting, “as such” using ranges of values as implemented in the phylogeny program TNT, and exclusion altogether. Results indicate that even the inclusion of only a few continuous characters dramatically increases the resolution of nodes. Despite the different treatments of continuous characters, major features of the trees are shared across all results. The subfamily Pterocephaliinae is restricted to genera which possess a concave anterior border. Relative stratigraphic placement was estimated using a composite section built in CONOP and used to scale the tree topologies and to assess stratigraphic consistency. Although previously hypothesized multispecies evolutionary series are not supported by the results, tree topology, stratigraphic distribution, and optimized character state transformation support the interpretation of several sister taxa as direct ancestor-descendent pairs.

Two new Mesozoic gastropod species, provisionally attributed to the minute (height < 5 mm) coiled neomphalid genus Retiskenea?, are described from three geographically isolated, Early Cretaceous, hydrocarbon seep-carbonate sites at Wilbur Springs, Rice Valley, and Cold Fork of Cottonwood Creek, northern California (USA). A fourth paleo-seep locality at Paskenta, of probable Upper Jurassic age, also yielded a single specimen of a morphologically similar microgastropod that may be a neomphalid with affinities to the Lower Cretaceous specimens described herein. the limestone lenses are ~2-260 m in length, ~1-5 m in diameter, and surrounded by forearc siliciclastics of bathyal turbidites or sedimentary serpentinites in the Upper Jurassic to Lower Cretaceous (Tithonian-Albian) Great Valley Group and its equivalents. the Lower Cretaceous microgastropods are tentatively placed in Retiskenea? based on similar shell characters: size, globose shape, inflated reticulate protoconch, number and distinct inflation of the body whorls, and fine, prosocline sculpture of the final body whorl. the fossils occur in carbonate microbialites that formed in seafloor sediments during archaeal anaerobic oxidation of methane in the zone of bacterial sulfate reduction, associated with H2S- and CH4-rich fluid seepage. the California Retiskenea? fossils commonly are found in gregarious clusters, or closely affiliated with thin worm tubes or, in one case, a larger gastropod.

These Mesozoic records increase the total known species attributable to this cold-seep endemic genus from two to four. Its spatial and temporal distribution thus may have spanned ~9,000 km around the Pacific Rim from at least ~133 m.y. to the present in 10 subduction-related seep sites from California (possibly Upper Jurassic-Lower Cretaceous), Washington (middle Eocene-Upper Oligocene), and modern offshore Oregon, the eastern Aleutians, and the Japan Trench. If the generic placement of these microgastropod fossils is correct, the California records are the oldest-known occurrences of Retiskenea, consistent with an estimated minimum Mesozoic origin for the 'hot vent' Neomphalidae, as inferred from molecular analyses published on other living members of the family.

The visceral skeleton (including complete mandibular, hyoid, and branchial arches) and teeth of the Lower Cretaceous hybodontid shark Tribodus limae are described based on well preserved fossil material. Jaw suspension and musculature are reconstructed, representing the first reconstruction of jaw musculature in a hybodont. The jaw suspension of Tribodus is similar to batoids and advanced galeomorphs in lacking direct cranio–palatine articulations and having skeletal jaw support by the hyoid arch alone (unlike most other hybodonts), but differs from batoids in that an intact hyoid arch is present. As in Asteracanthus and Lonchidion, the jaws do not extend to the snout, and were connected symphysially but not fused. CT scanning reveals the presence of supportive ‘trabecular cartilage’ struts in force-bearing regions of the jaws, representing the first report of these structures in an extinct chondrichthyan. Five branchial arches are present, of which pharyngobranchial, epibranchial, and ceratobranchial elements are observed although hypobranchials and basibranchials were presumably also present. A pharyngobranchial blade is present, as in some other hybodonts (e.g., Lissodus) and extant galeomorphs (e.g., Heterodontus), and the posteriormost pharyngobranchials are unfused. Tribodus is considered durophagous, based on presence of ‘trabecular cartilage’ struts and a weakly heterodont monognathic pavement dentition of flattened hexagonal teeth, as in extant myliobatoid rays. SEM examination shows that teeth of T. limae are anaulacorhize with a double layer of single crystallite enameloid (SCE), and confirms the presence of columnar osteodentine, as in other Acrodontidae.

Recognition of ontogeny within a stenolaemate bryozoan colony requires separating the individualistic aspects of a zooid's growth from those of its neighbors. The ancestrula is the only zooid within a colony that always displays a partially independent ontogeny that ceases when it starts to experience shared changes with its neighboring daughter zooids during subsequent accretionary skeletal growth.

Stenolaemate astogeny (shared changes across multiple zooids during the growth of both the ancestrular zooid and its asexual descendants) includes all coordinated changes in the size, shape, number, and calcification of autozooids, polymorphs, and extrazooidal structures, as well as changes within autozooids or polymorphs, such as the formation of basal diaphragms and brown bodies. Despite the fact that many of these directional changes occur within individual zooids, they are not part of ontogeny because they are taking place simultaneously across zooids that share a common skeleton, extrazooidal tissues, and pseudocoelomic spaces.

Shared directional multizooidal changes occurring during colony growth provide a confirmatory test for the existence of astogeny. Astogeny was statistically evaluated in 6–15 characters measured within the exozones of four colonies of Tabulipora carbonaria (Worthen in Worthen and Meek, 1875). Statistically significant (at P ≤ 0.05) directional changes took place across growth stages within the exozone in the following morphometric characters: zooecial density, zooecial wall surface area, acanthostyle density, zooecial wall thicknesses, maximum acanthostyle diameters, and intrazooecial diaphragm abundances. Overall, earlier exozonal growth stages differ statistically from those of the later exozone, with characteristics of intermediate growth stages intergrading between the two. Discriminant function analysis segregated intervals of exozonal growth into early-, intermediate-, and late-stage clusters, confirming patterns delineated by univariate statistical tests.

Based on these exozonal growth patterns, heterochronic changes in exozone astogeny characterized evolution within and across species of Tabulipora. Onshore populations of T. carbonaria were astogenetically progenetic relative to offshore ones along an environmental gradient across Kansas, whereas local populations became temporally more hypermorphic in a short-term stratigraphic succession of similar environments. Tabulipora carbonaria originated by astogenetic recapitulation in populations of its probable ancestor, T. ramosa. Therefore, speciation, microevolution, and clinal variation in Tabulipora all involved heterochronic modifications of exozone astogeny.

This paper demonstrates, for the first time, the existence of an inner partition (limen) in females of Kloedenella Ulrich and Bassler, 1908, and the presence of a juvenile carapace in the brood chamber of Poloniella tertia Kroemmelbein, 1953. These facts indicate that the Kloedenellidae Ulrich and Bassler, 1908, and the living platycopes are closely related. Thin sections of female carapaces in kloedenellids, some cytherellids and a geisinid-like form, indicate that their posteriorly inflated valve walls are only half as thick as the remaining parts. This suggests that the feature developed in different lineages and had a pure adaptable character. A historical and critical survey of the kloedenellid literature is included. The latter involves a discussion of phylogenetic relationships between this group and other non-myodocopide ostracodes. In light of new facts and data reported earlier, revised diagnoses for the Kloedenellidae and Paleozoic Cytherellidae Sars, 1866, are presented.

Twelve brachiopod taxa are described from the Early Devonian (probable early Emsian) Pa Samed Formation of southern Thailand, including the new genus and species Quasiprosserella samedensis (Ambocoeliidae?) and the new species Plectodonta forteyi, Caplinoplia thailandensis, and Clorinda wongwanichi. They are the first undoubted Devonian brachiopods from Thailand. They represent the deeper-water Benthic Assemblages BA4-5, and, although clearly indicative of the Old World Realm, cannot be assigned to a particular biogeographical region. A new undescribed fauna from the contemporary Zebingyi Formation of Burma (Myanmar) is also noted.

Brachiopods assigned to eight genera and 15 species have been recovered from Upper Cambrian (Franconian and Trempealeauan Stages) and lowest Ordovician strata in the Arbuckle and Wichita Mountains of Oklahoma. Species of Ocnerorthis and Eoorthis occur in the Reagan Sandstone and Honey Creek Limestone of the Timbered Hills Group. Species of Billingsella appear in the Honey Creek and range upward into the overlying Fort Sill and Signal Mountain Limestones of the Arbuckle Group. Species of Cymbithyris, Finkelnburgia, Nanorthis, and Apheoorthis succeed each other upsection in the Signal Mountain Limestone. Five brachiopod zones and one subzone have been established that can be used to correlate the measured sections in the Arbuckle and Wichita Mountains, and to correlate with varying degrees of confidence from Oklahoma to similar brachiopod occurrences in other areas in the United States.

We report the oldest fossil occurrence of freshwater potamolepid sponges (Demospongiae, Spongillina, Potamolepidae) to date, originating from middle Eocene lake sediments accumulated in the Giraffe kimberlite maar, northern Canada. Sponges are represented by strongyle spicules that are gemmuloscleres. These are described herein as belonging to a new species, Potamophloios canadensis. Because the most similar extant potamolepid sponges inhabit subtropical to tropical water bodies, these observations provide further evidence of biogeographic reorganizations in response to warm high-latitude Eocene paleoclimates.

New samples of fusulinids collected in the Tengchong Block, western Yunnan, China, are systematically studied and presented here. The fusulinid fauna from the Xishancun section in the Shanmutang area is dominated by Chusenella and Nankinella, whereas that from the Shuangheyan area is composed mainly of Chusenella and Schwagerina. Both faunas are dated as Roadian–Capitanian (middle Permian). These new findings are integrated with fusulinid taxa reported earlier from the block to demonstrate the taxonomic features and paleogeographic significance of Permian fusulinids. The low generic diversity through early and middle Permian and the paucity of middle Permian neoschwagerinids and verbeekinids in the block confirm its Gondwana-affinity attributes. Moreover, the Permian fusulinids of the Tengchong Block are depauperate; i.e., consisting of a limited number of species with abundant individuals. This particular feature commonly suggests an inhospitable environment, and carbonates of varied facies containing these faunas in the Tengchong Block suggest a facies-independent factor as the reason, most likely the relatively low temperature of seawater.

Ceratopsids, horned herbivorous ornithischians from the Cretaceous of North America, are unique among dinosaurs in the form and expression of their cranial ornamentation. All ceratopsid genera possess a bony parieto-squamosal frill that projects over the neck region and some degree of development of nasal and orbital horns. These horns vary in form and location, from low bosses (e.g., Pachyrhinosaurus Sternberg, 1950) to long, conical horns (e.g., Triceratops Marsh, 1889 postorbital horns). Internal structural changes occurred along with these extreme external modifications of the skull (Forster, 1996).

Fourteen species of brachiopods were collected from two measured sections on Khios, and although the sections are only about 4 km apart, they contain but one genus in common. Both collections are from the zone of Neoschwagerina, but the collection from the hill called Seladha is probably somewhat younger than the collection from the region called Agrelias, because it is accompanied by the first appearance of the fusulinid Verbeekina. The brachiopods at Agrelias are: Kotlaia aethopa n. gen. and sp., Schuchertella tapina n. sp., Derbyia dirata n. sp., Meekella megala n. sp., Seseloidia phlebodes n. gen. and sp., Tschernyschewia sp. indet., Marginifera ganota n. sp., Entacanthadus chioticus n. gen. and sp., Horridonia sp. A., and Linoproductus cf. L. lineatus Waagen. The fauna at Seladha contains: Linoproductus cf. L. lineatus, Composita sp. indet., Squamularia sp. indet., Hustedia sp. indet., and Timorina sp. indet. Both faunas are dated as middle Permian, Kungurian, perhaps equivalent to the lower and upper parts of the Wordian of North America. The type species of Kotlaia is K. capillosa n. sp. from the Permian of the Salt Range, Pakistan, and a new genus of hercosiid (Sicularia) from the Permian of Sicily is introduced for nomenclatural reasons, with type species Richthofenia sicula Gemmellaro.