The study of specimens of the retiolitid graptolites Stomatograptus sp., and Agastograptus robustus with a complete or nearly complete periderm permits a better understanding of the growth and development of retiolitids. Incremental layers deposited in more or less concentric layers on skeletal lists are synchronized with the deposition of sheetlike fusellar bands between the lists. Lists, therefore, become progressively more robust, while the periderm of fusellar bands remain single-layered. It appears that before the development of new distal thecal lists and concomitant deposition of fusellar bands can begin, the next proximal-most thecae must be essentially complete. Retiolitid graptolite thecal growth thus appears to mirror that of “normal” graptolites.

New aulacopleuroidean trilobites from the Lochkovian of Oklahoma include the otarionine Cyphaspis carrolli new species from the Haragan Formation, and the brachymetopid Cordania wessmani new species from the overlying Bois d'Arc Formation. Cyphaspis carrolli is the first record of the genus from the North American Devonian. It is a highly plesiomorphic species, dissimilar to contemporaries from Europe, but closely related to Silurian species from Northern Laurentia and England. Cordania wessmani had previously been interpreted as a possible sexual dimorph of Cordania falcata Whittington, 1960, but new material and information shows that the forms occur separately with no stratigraphic overlap. New information on trilobite occurrence in the Haragan and Bois d'Arc Formations does not support previous hypotheses of trilobite sexual dimorphism, but rather indicates the presence of distinct, stratigraphically successive faunas.

Several dinosaurs, notably Ouranosaurus and Spinosaurus, have vertebral columns marked by prominent arrays of elongated neural spines. Using pelycosaurian sailbacks like Dimetrodon as analogies, popular orthodoxy holds that the tall spines served as supporting struts for dorsal sails of purported thermoregulatory function, especially heat dissipation in tropical climates. It is argued here that the neural spines of Ouranosaurus, Spinosaurus, and several other long-spined dinosaurs favor bison-like humps rather than sails: 1) in functional morphology and relative elongation they are dissimilar to pelycosaur spines but homoplastically converge on the spines of high-withered ungulates; 2) the usefulness of a sail in thermoregulation has been exaggerated—in large tetrapods it would have been fairly efficient as a thermal amplifier but ineffective as a radiator; hence large sail-bearing dinosaurs in open tropical climates are improbable; 3) the insulation properties of humps favor gigantothermy, the most likely thermobiological model for large dinosaurs.

Dinosaur humps are probable adaptations for: 1) energy storage, maintenance of gigantothermy, and heat-shielding in unshaded habitats; 2) long-distance migration from feeding to nesting grounds across terrains of variable productivity; and 3) lipid conservation for production of large clutches of eggs at the nesting site. Because sacral, caudal, or dorsal humps were relatively common traits among certain groups, the fashionably anorexic image of many large dinosaurs must be emended.

A nearly complete skull of Anchitheriomys from the Miocene of Nebraska allows description of the cranial foramina. In skull characters, Anchitheriomys most closely resembles Agnotocastor and Neatocastor among castorids; it retains primitive features that it shares with eutypomyids (position of the posterior palatine foramina, smooth palatal surface, nearly parallel tooth rows, retention of dP3) combined with derived features (elongate rostrum, procumbent incisors) that are shared only with Agnotocastor and Neatocastor. A new subfamily, Agnotocastorinae, is erected for this group of primitive beavers.

Systematic restudy of Lower Mississippian disparid crinoids from the midcontinental United States results in the recognition of nine valid species and one left in open nomenclature. Although disparid crinoids are not diverse, they may be locally abundant and be the dominant crinoids in certain settings. The following species are considered valid: Catillocrinus tennesseeae Shumard, Catillocrinus wachsmuthi (Meek and Worthen), Eucatillocrinus bradleyi (Meek and Worthen), Halysiocrinus bradleyi (Meek and Worthen), Halysiocrinus cumberlandensis new species, Halysiocrinus springeri Brower, Halysiocrinus tunicatus (Hall), Synbathocrinus blairi Miller, and Synbathocrinus swallovi Hall. Several species are placed into synonymy. Catillocrinus shumardi Springer and C. turbinatus are considered junior synonyms of C. tennesseeae. Halysiocrinus granuliferus and H. perplexus are regarded as junior synonyms of H. tunicatus. Synbathocrinus angularis Miller and Gurley, S. granulatus (Wood), S. granuliferus Wetherby, S. robustus Shumard, and S. troosti (Wood) are deemed junior synonyms of S. swallovi. The youngest (Meramecian) North American calceocrinids, Halysiocrinus sp., are reported, herein, from the Harrodsburg and Salem Limestones of Indiana.

Twelve fused clusters of conodont elements representing the apparatus of Belodina compressa (Branson and Mehl, 1933) were recovered from the Plattin Limestone (Turinian) near New London, Missouri, and Hanover, Iowa. These clusters show that the apparatus of B. compressa consisted of four morphologically distinct elements: eobelodiniform (M), compressiform (S1), grandiform (S2), and dispansiform (S3) elements. All four element types are also present in fused clusters of B. confluens Sweet, 1979, supporting the interpretation that Belodina had a quadrimembrate apparatus. The B. compressa clusters were recovered from pellet-rich wackestones that yielded relatively large and diverse conodont faunas, in which only the elements of B. compressa were fused. The elements of B. compressa present in the fused clusters may have been deposited in fecal pellets, where a higher concentration of calcium phosphate, combined with the relatively large surface area contacts between B. compressa elements, facilitated the fusing of these elements into clusters. These fused clusters provide the basis for interpretation of the apparatus architecture of Belodina.

Recently collected specimens of Catopsalis fissidens from the Torrejonian interval of the Nacimiento Formation in the San Juan Basin, New Mexico significantly augment knowledge of the morphology and dental variability of the species. This new knowledge suggests C. foliatus Cope, 1882 (=C. johnstoni Fox, 1989) is a valid Puercan species and that C. fissidens Cope, 1884a is a subjective senior synonym of C. utahensis Gazin, 1939. This latter synonymy further increases taxa shared between the Dragon Canyon local fauna of Utah and the Torrejonian fauna of the San Juan Basin, thus supporting previous inclusion of the Dragonian land-mammal “age” in the Torrejonian.

Species of Eugonophyllum (Codiaceae, Chlorophyta) have traditionally been characterized as phylloid or leaf-like. But a reconstruction of well preserved specimens of Eugonophyllum, probably E. johnsonii Konishi and Wray, from Upper Pennsylvanian limestone formations of Palo Pinto County, Texas, indicates it was cyathiform or cup-shaped. Reconstruction was based on the forms of membranes as seen in sections and on partial excavation of thalli. This Eugonophyllum shared with congeneric species of Eugonophyllum the characteristic two-layered cortex (outer and inner), and with other codiaceans the same general membrane structure consisting of bilateral cortices with palisades of utricles now filled with micrite, and a medulla of tubular coenocytes, an area now mostly filled with mosaic sparry calcite. A cyathiform thallus would have inner and outer cortices but no differences were found in the structure of the inner and outer cortical utricular casts. The thalli were apparently anchored with elongated, cylindrical holdfasts. Internal spherical structures, presumably developed from differentiated utricles, may have been zygotes or young embryos from an oogamous fertilization. These were apparently released to the environment through the membrane.

Several specimens of the Late Cretaceous lamniform shark, Cretoxyrhina mantelli (Agassiz), from the Niobrara Chalk of Kansas suggest that the shark fed on teleosts, mosasaurs, and possibly plesiosaurs. These animals are active vertebrates, so C. mantelli probably occupied the apex of the food chain in the Late Cretaceous seas. This top predator, however, was probably scavenged frequently by anacoracid sharks. Carcharodon carcharias (great white shark) and carcharhinid sharks are considered as the modern guild counterparts for Cretoxyrhina mantelli and anacoracids, respectively.

The taxonomy of the predominantly Australian fossil dipnoan genus, Neoceratodus, is revised and the Recent Australian lungfish, Neoceratodus forsteri, and two fossil species, Neoceratodus eyrensis and Neoceratodus nargun, are redefined. Two new species of the related Tertiary genus, Mioceratodus, are described on the basis of tooth plates from central and northern localities in Australia. These are Mioceratodus diaphorus and Mioceratodus poastrus. A new genus, Archaeoceratodus, is erected to include three rare Tertiary species and one Mesozoic species. The Tertiary members of this genus are the type species, Archaeoceratodus djelleh, described originally as Neoceratodus djelleh, and two new species, Archaeoceratodus rowleyi and Archaeoceratodus theganus. The Mesozoic species is Archaeoceratodus avus from Triassic and Cretaceous deposits in southeastern Australia, described originally as Ceratodus avus. All three genera belong in the family Neoceratodontidae.

The record of fossil land mammals from Antarctica has been restricted previously to the middle levels of the Eocene-?early Oligocene La Meseta Formation in Seymour Island, Antarctic Peninsula. This mostly shallow-marine sequence was divided informally into seven subunits (Tertiary Eocene La Meseta or TELM 1 to 7) by Sadler (1988). Land mammals, representing South American lineages of marsupials, edentates, and ungulates were recovered from TELM 3, 4, and 5 (Marenssi et al., 1994; Vizcaíno et al., 1994). The purpose of the present note is to report the discovery of a well-preserved ungulate tooth from the uppermost level of the La Meseta Formation (TELM 7) and to discuss its paleoenvironmental implications.

The archosaur fauna from the Woodbine Formation (Cenomanian), Tarrant County, Texas includes crocodiles, theropod, nodosaurid, and hadrosaurid dinosaurs. A new neosuchian crocodile, Woodbinesuchus byersmauricei new genus and species, appears to be a longirostrine goniopholid. Isolated theropod teeth include morphotypes similar to Richardoestesia. Nodosaurid premaxillary teeth are unique among early nodosaurids in having no marginal cusps. Hadrosaurid remains represent the oldest hadrosaurs east of the Western Interior Seaway.

Purgatorius titusi, represented by 51 teeth and jaw fragments, is described from the lower Paleocene Bear Formation of the Crazy Mountains Basin in south-central Montana. Several synapomorphies, including a weak postprotocingulum and mesial inflection of molar trigonids, are indicative of the taxon's “plesiadapiform” affinities. Other features, such as wider stylar shelf and a less squared lingual outline on upper molars, are more primitive than those of Purgatorius unio, heretofore the earliest occurring species of well-represented primatomorphs.

Late Cretaceous dinosaur eggshell assemblages from six localities of the Tremp basin (Southern Pyrenees, Lleida, Spain) are studied and compared with those of Southern France, to correlate their temporal succession. Fontllonga 6 reveals the most diverse eggshell assemblage known so far, with seven oospecies, among which one new structural type (Pseudogeckoolithus nodosus new genus and species), a new Ratite-type eggshell (Ageroolithus fontllongensis new genus and species) and a new Prismatoolithidae are described; four other taxa are shared with Southern France. The correlation of both Spanish and French eggshell successions allows us to recognize three main periods characterised by different eggshell assemblages: a lower assemblage with Megaloolithus petralta, M. aureliensis, Prismatoolithus tenuis and P. matellensis from the French Lower Rognacian and the Spanish sites Fontllonga 6 and Moro; a middle one with M. siruguei from the Middle Rognacian and Biscarri; and a late one from the Late Rognacian with M. mammilare (from Abella and Bastus) and M. pseudomamillare (from Suterranya). Some contradictions appear when comparing results with paleomagnetism and charophyte correlations but the eggshell correlations are consistent with other stratigraphic studies.

Isoetes beestonii new species is the most ancient known species of this living genus. In earliest Triassic shales of the Sydney and Bowen Basins of Australia it is locally abundant as circlets of transversely wrinkled leaves. It was heterosporous with megaspores of Maiturisporites rewanensis and microspores of Lundbladispora sp. cf. L. springsurensis.

Isoetes thus predates Pleuromeia from which it has been thought to have evolved. Australian Pleuromeia-like subarborescent lycopsids are here reviewed as whole plants, with names based on fertile structures, and include Cylostrobus sydneyensis Helby and Martin from the Sydney Basin, Pleuromeia dubia (Seward) Retallack from the Sydney and Canning Basins, and Cylostrobus indicus (Lele) new combination and Pleuromeia sternbergii (Münster) Corda for Germar, newly recorded from the Canning Basin.

There are in addition an array of cormose lycopsids that formed compact conelike plants when fertile, intermediate in stature between Isoetes and Pleuromeia. One of these is Tomiostrobus australis (Ash) Sadovnikov, formerly regarded as a cone, but here reinterpreted as a small pioneering plant of oligotrophic lakes and ponds, like Isoetes. Its megaspores are Horstisporites and its microspores are the stratigraphically important Aratrisporites tenuispinosus. Other similar forms are Tomiostrobus polaris (Lundblad) new combination from the early Triassic of Greenland, T. mirabilis (Snigirevskaya) new combination from the early Triassic of the Tunguska Basin of Siberia, T. taimyrica (Sadovnikov) new combination from the Early Triassic of the Taimyr region of Siberia, Lepacyclotes ermayinensis (Wang) new combination from the middle Triassic of China, L. convexus (Brik) new combination from the middle-late Triassic of Kazachstan, and L. zeilleri (Fliche) new combination from the middle Triassic of France and Germany.

The diversity of isoetaleans in early Triassic floras and the weak vascular system of permineralized Tomiostrobus and Pleuromeia contradict the traditional view that Isoetes evolved by reduction in size from Pleuromeia and that its opportunistic life style allowed it to avoid plant competition. It is now more likely that Isoetaceae were weedy survivors of Permian-Triassic extinctions. The adaptive radiation and decline of Triassic quillworts matches the recovery from near-extinction, then decline of therapsid reptiles, for which these plants may have been an important food.

The purpose of this note is to record the availability for research of highly fossiliferous sediment from a late Pleistocene terrestrial deposit in the Caribbean. The Red Hills Road cave in the parish of St. Andrew, northwest of Kingston, Jamaica (for more precise locality information, see Donovan et al., 1995, p. 12-15) is a late Pleistocene, essentially unstratified, cave deposit. The terrestrial fauna from this site includes diverse vertebrates (Savage, 1990; D.A. McFarlane and R.D.E. MacPhee, research in progress) and gastropods, associated with rare arthropods including millipedes (Donovan and Veltkamp, 1994), isopods, ostracodes and claws of non-marine crustaceans (J. S. H. Collins, research in progress).

While preparing the part of the Treatise on Invertebrate Paleontology dealing with Greenfieldia, Alvarez had problems with the absence of information regarding its jugum. GRABAU (1910, in Grabau and Sherzer) described the smooth, subequally biconvex, small shell Greenfieldia whitfieldi, the type species of his Greenfieldia, from the Late Silurian Greenfield Dolomite of northern Ohio. Grabau (1910, p. 149) remarked that the brachidium was unknown, with only the presence of laterally directed spiralia (Grabau, Pl. XXX, fig. 9) being indicated but not discussed in the text. Grabau (1910) considered a questionable assignment of Greenfieldia to the meristelloid Hindella. Boucot et al. (1965, p. H662), Berry and Boucot (1970, p. 155) and Berdan (1972, p. 16) all illustrated the difficulty in discriminating between the Late Silurian Protathyris, whose jugum is known and athyroid in type, and Greenfieldia with its unknown jugum. Jones (1978, p. 10) further emphasized the difficulty in discriminating between Protathyris and Greenfieldia owing to ignorance of the latter's jugum. Modzalevskaya (1979, fig. 7) described a jugum from a form assigned to Greenfieldia. The complex form of the jugum she illustrated, featuring a number of recurving branches, is entirely unlike that of Greenfieldia although relatively similar to that of Protathyris.

New material of Gasparinisaura cincosaltensis from the Río Colorado Formation (Upper Cretaceous) of northwestern Patagonia (Río Negro Province, Argentina) provides seven new characters that are interpreted as autapomorphies of the species: 1) four true sacrals; 2) first sacral rib not coalescent with second sacral rib; 3) long pubic peduncle of ilium; 4) absence of anterior intercondylar groove on femur; 5) both malleoli of the tibia approximately at the same level; 6) metatarsal II posteriorly compressed laterally; and 7) low ascendant process of the astragalus. A phylogenetic analysis of selected ornithopods indicates that Gasparinisaura cincosaltensis is the most plesiomorphic Euiguanodontia. A complete absence of hatchlings indicates that Cinco Saltos was not a nest site.

The editor of the Zoological Record has kindly informed me that the generic name Polysiphonia Finks, 1995, (class Calcarea, order Murrayonida, family Maeandrostiidae) (Finks, 1995, page 4) is preoccupied (Mrs. M. Joan Thorne, personal commun., 1996). I therefore rename it Polysiphonaria.