Trends are the primary phenomenon of macroevolution, but they have often been misinterpreted because an old and deep conceptual error has induced us to misread, as anagenesis in abstracted entities, a pattern that actually records changes in variance by increase or decrease in diversity or disparity among species within clades. These patterns are actually produced by the “entity making and breaking machine” of differential species success, but we misread history as anagenesis because we focus on extreme values (though they may only represent tails in variance of a system), or on measures of central tendency that shift passively as species birth and death work in their differential way. I discuss several examples in two classes: “increase trends” mediated by growth in variance, and “decrease trends” produced by diminution of diversity or disparity. I present two examples in extenso based on original data: threefold occurrence of Cope's rule in planktonic foraminifers as a consequence of increasing species diversity from small founding lineages (increase trend), and disappearance of 400 hitting in baseball as a decrease trend recording symmetrical decline of variance with increasing excellence of play, not the gradual extinction of a valued “thing.” A proper appreciation of trends as changes in variance flows from and into the two most important revisionary themes in modern evolutionary theory: 1) constraint and structure as an antidote to overreliance upon adaptation (questions about why founding lineages tend to be small, and why size ranges are constrained, lie primarily in structural, not adaptational, domains); 2) hierarchy (increase and decrease trends are powered by differential species sorting, not by extrapolated anagenesis of competition among organisms within populations).

The Cretaceous Kodiak Formation at the northeastern end of Kodiak Island, Alaska, is interpreted to have been deposited in a distal deep-sea fan complex. Facies analysis of the sequence suggests deposition in channels (both major and distributary), lobe fringe (proximal and distal), and interchannel and interchannel/channel mouth environments. The strata contain a diverse and relatively abundant trace fossil assemblage consisting, at the ichnogeneric level, of twenty-six forms: Acanthorhaphe, Chondrites, Circulichnis, Cochlichnus, Cosmorhaphe, Desmograpton, Glockerichnus, Gordia, Helminthoida, Helminthopsis, Muensteria, Neonereites, Nereites, Paleodictyon, Palaeophycus, ?Phycosiphon, Planolites, Protopaleodictyon, Scolicia, Spirophycus, Spirorhaphe, Taenidium, Taphrhelminthopsis, Terebellina, Thalassinoides, and Yakutatia.

Thirty-eight ichnospecies are described, three of which (Acanthorhaphe ichnosp., Cosmorhaphe helicoidea, and Desmograpton fuchsi) are recorded for the first time in North America. Final channel-fill (levee) and interchannel environments contain the most abundant and diverse ichnoassemblages, a reflection of favorable environmental parameters for inhabitation by benthic organisms, but more importantly the presence of diverse lithotypes conducive to the final preservation of their activity. Channel-fill sequences are devoid of trace fossils, a reflection of substrate mobility and lack of shale interbeds precluding toponomic preservation. Lobe fringe sequences contain only isolated trace fossils, a reflection of their poor exposure and largely monolithologic character.

The ichnoassemblage is compared to 20 previously described and taxonomically well-documented deep-water flysch trace fossil studies from the Phanerozoic. Comparison at the ichnogeneric level is favorable with only Acanthorhaphe, Terebellina, and Yakutatia being relatively unique to the Kodiak sequence.

Molds of corals, bivalves, and gastropods in the Oligocene–Miocene Bluff Formation of Grand Cayman Island contain casts of Entobia (nine ichnospecies including the new ichnospecies E. dendritica), Trypanites (three ichnospecies), Gastrochaenolites (two ichnospecies), Maeandropolydora (one ichnospecies), Talpina (one ichnospecies), and Caulostrepsis (one ichnospecies), as well as the new ichnogenus Uniglobites, indeterminate ichnogenus A, and a problematical boring. Entobia accounts for about 75 percent of the borings, while Uniglobites and Trypanites together account for 15 percent of the borings. Comparison of Uniglobites with modern borings of known affinity suggests that it was produced by adociid and/or clionid sponges while indeterminate ichnogenus A was probably formed by bivalves. The amount of boring, which ranges from 0 to 75 percent, varies from skeleton to skeleton or, in some cases, from branch to branch of the same coral colony. The branching coral Stylophora was particularly susceptible to boring, probably because of its small size and high surface area. The average boring of about 38 percent compares favorably with the amount of boring found in modern corals. Analysis of the borings suggests that sponges were responsible for most of the borings in the corals from the Bluff Formation. Comparison with bioerosion in modern reefs suggests that similar patterns of bioerosion were also occurring in Oligocene–Miocene times.

The stratotype for the Bashkirian Stage of the Soviet Middle Carboniferous is located on the Askyn River in Gornaya Bashkiria (western slope of south Urals). Twenty-four rock samples, mostly from the lower part of the section, yielded abundant and diverse assemblages of calcareous foraminifers which are systematically described and illustrated here for the first time.

The foraminiferal assemblage from the Siuransky Horizon at the base of the Bashkirian is essentially identical to that from the top of the underlying Lower Carboniferous Serpukhovian Stage. Thus, foraminifers do not provide a basis for identifying the Soviet Lower–Middle Carboniferous boundary. This notwithstanding, the presence of the foraminifer Globivalvulina bulloides (Brady) (=G. moderata Reitlinger) and the conodont Idiognathodus parvus (Dunn) in both the upper Serpukhovian and Bashkirian indicates that the base of the Bashkirian can be no older than medial to late Morrowan of the North American succession. The primitive fusulinid Pseudostaffella (Pseudostaffella) appears at the bases of the lower Bashkirian Akavassky Horizon and the North American Atokan Series. The base of the Akavassky is interpreted to be somewhat older than early Atokan, however, because Ps. (Pseudostaffella) appeared in the Urals in phylogenetic continuity with its immediate ancestor, whereas in most of North America it was an immigrant.

The type Bashkirian succession contains a seemingly complete phylogeny from advanced eostaffellids to primitive fusulinids. Plectostaffella jakhensis, immediate ancestor to the fusulinids, arose from a member of the Eostaffella postmosquensis plexus in the late Serpukhovian. Plectostaffella jakhensis, in turn, gave rise to Ps. (Semistaffella) variabilis in the early Bashkirian (late Siuransky), from which evolved Ps. (Ps.) antiqua shortly thereafter (earliest Akavassky). An as yet unidentified but advanced species of Ps. (Pseudostaffella) is the most likely ancestor to late Bashkirian Neostaffella ivanovi. The evolutionary series leading from the E. postmosquensis plexus to primitive Neostaffella apparently developed exclusively in the Eurasian–Arctic faunal realm, as Pl. jakhensis, Ps. (Semistaffella) variabilis, and Ps. (Ps.) antiqua are unknown in the Midcontinent–Andean region. Diverse Ps. (Pseudostaffella) spp. appeared in the latter area pursuant to an adaptive radiation aided by periodic interchange between faunal realms.

Despite numerous distributional studies of foraminifera in modern shallow-water carbonate environments, information loss and taphonomic bias in the transition from life to death assemblages of foraminifera in these environments have not previously been examined in detail. Surface sediment and vegetation samples were collected along six nearshore traverses and one traverse across the back reef lagoon off Key Largo, Florida. Living foraminifera are found in abundance on algae and the marine angiosperm, Thalassia testudinum, while foraminifera in sediment assemblages are represented primarily by empty tests. Q-mode cluster analysis of living assemblages on Thalassia delineates inshore (depth 0.4–2.7 m) and offshore (3.0–9.0 m) back reef biofacies. Calcareous imperforate (suborder Miliolina) species thrive in quiet waters of the inshore biofacies, in which biotic interactions appear to be the prime factor in determining small-scale species distributions of living foraminifera. Fragile species are most susceptible to test destruction, and, therefore, sediment assemblages are dominated by more robust forms (e.g., Archaias angulatus, Valvulina oviedoiana, thick-walled species of Quinqueloculina).

Water turbulence primarily determines species composition of living populations of the offshore biofacies. These assemblages are dominated by the calcareous perforate (suborder Rotaliina) species Planorbulina acervalis and Rosalina bahamaensis. These species resist transport by encrusting Thalassia blades and having a test which fits flush with grass blades, respectively. However, sediment assemblages of the offshore biofacies are also dominated by typical inshore, robust species (Archaias angulatus, thick-walled miliolids). Thus, inshore and offshore biofacies are not readily differentiated by Q-mode cluster analysis of sediment assemblages. Robust species are wide ranging and often abundant in sediment because of differential preservation and time-averaging of sediment assemblages. The resultant taphonomic bias may interfere with paleoecologic interpretations concerning intensity of water energy and distance from shore.

Stromatoporoids are the principal framebuilding organisms in the patch reef that is part of the reservoir of the Normandville field. The reef is 10 m thick and 1.5 km2 in area and demonstrates that stromatoporoids retained their ability to build reefal edifices into Famennian time despite the biotic crisis at the close of Frasnian time. The fauna is dominated by labechiids but includes three non-labechiid species. The most abundant species is Stylostroma sinense (Dong) but Labechia palliseri Stearn is also common. Both these species are highly variable and are described in terms of multiple phases that occur in a single skeleton. The other species described are Clathrostroma cf. C. jukkense Yavorsky, Gerronostroma sp. (a columnar species), and Stromatopora sp. The fauna belongs in Famennian/Strunian assemblage 2 as defined by Stearn et al. (1988).

Two Upper Triassic sphinctozoan sponges of the family Sebargasiidae were recovered from silicified residues collected in Hells Canyon, Oregon. These sponges are Amblysiphonella cf. A. steinmanni (Haas), known from the Tethys region, and Colospongia whaleni n. sp., an endemic species. The latter sponge was placed in the superfamily Porata by Seilacher (1962). The presence of well-preserved cribrate plates in this sponge, in addition to pores of the chamber walls, is a unique condition never before reported in any porate sphinctozoans. Aporate counterparts known primarily from the Triassic Alps have similar cribrate plates but lack the pores in the chamber walls. The sponges from Hells Canyon are associated with abundant bivalves and corals of marked Tethyan affinities and come from a displaced terrane known as the Wallowa Terrane. It was a tropical island arc, suspected to have paleogeographic relationships with Wrangellia; however, these sponges have not yet been found in any other Cordilleran terrane.

The early tabulate coral Lamottia heroensis has been identified from the Ion Member of the Decorah Formation (Upper Ordovician) in northeast Iowa. This extends the stratigraphic range of this species upward from Lower Chazyan to Kirkfieldian, and extends the geographic range from the Vermont-New York border area to include the north-central Midcontinent. Thin section and SEM studies strongly support the contention that the longitudinal pattern of alternating light and dark bands observed in corallite walls reflects a primary structural grain rather than a secondary diagenetic feature.

A collection of 6,151 bryozoan colonies (two cyclostome species from two families, and 73 cheilostome species from 30 families) from the leeward fringing reef of Bonaire, Netherlands Antilles, is largely, but not entirely, of Caribbean affinities, with some links to Indo-Pacific populations. The bryozoans from Bonaire show some relation to water depth at species and higher taxonomic levels, but these relations are not clear-cut. Many of the species are found through all or most of the 73 meter depth range sampled, but a few are limited to shallow water, and some to deeper water. At a higher taxonomic level, some families (e.g., Calloporidae, Bugulidae, Smittinidae) include wide depth-ranging species, shallow-water species, and deep-water species; this indicates some divergence between species and family-level depth distributions. Several calculated diversity indices show variable trends with increasing water depth, with at most only slight increases with depth. The bryozoans in this southern Caribbean reef assemblage do not show the well-defined depth zonation of corals. However, the recognition of deep- and shallow-water assemblages containing diagnostic species does show that cryptic reef-dwelling bryozoans have paleoecological utility as depth indicators in ancient reefs.

This report describes a previously unknown chevron color pattern preserved on the Carboniferous bivalve Streblochondria? and discusses the significance of color patterns on Paleozoic bivalves as a group. Analysis of Paleozoic color pattern distribution suggests that the appearance of predators in the Devonian may have influenced preferential evolutionary selection for the development of color patterns in bivalves.

A new raphistomatinid genus, Wisconsinella, from the Middle Devonian of Wisconsin is described. The type and only known species is Wisconsinella clelandi n. sp. from the Lake Church Formation of late Eifelian age. The new genus is characterized by its highly angular whorl profile and low gradate spire. It is distinguished from all other known raphistomatinid genera by the presence of a narrow, steeply inclined outer whorl surface, demarked both above and below by a sharp, strong angulation.

Chlamydotheca llanoensis is a new species of freshwater ostracode found in latest Pleistocene (12,000–10,000 years B.P.) fluviatile sediments on the Southern High Plains. At the type locality (Lubbock Lake Archaeological Site, Lubbock County, Texas) and at two other localities, C. llanoensis was associated with streamside Paleo-Indian artifacts. This easily recognized species should be a useful guide fossil for correlation of strata of similar environment and age on the Southern High Plains.

Rhabdosomes of Brevigraptus quadrithecatus n. gen., n. sp. (Lasiograptinae, Diplograptacea), from the Upper Ordovician Viola Springs Formation of south-central Oklahoma, comprise four fully developed thecae. The sicula and the first two thecae are fully sclerotized. The ultrastructure of the fusellum is unusually dense but is overlaid by a typical diplograptacean bandaged cortex. The third and fourth thecae consist of clathria covered by a cortical sheet. Lacinia are absent. The cortical sheet comprises bandages deposited in a support dominated pattern that matches expectations of the pterobranch model of peridermal secretion. Lists are fusellar derivatives and exhibit traces of fuselli-like growth increments but no continuous fusellum is present. Lists are strongly thickened with cortical tissue. The fabricational pattern employed in list construction reveals the operation of strong historical constraints during the evolutionary reduction of the fusellum.

The thecal form and list architecture of Brevigraptus quadrithecatus are nearly identical to those of Pipiograptus hesperus Whittington. Brevigraptus quadrithecatus possesses a Pattern G astogeny and exhibits several derived astogenetic features that it shares with P. hesperus and Orthoretiolites hami Whittington. Both thecal and astogenetic similarities suggest the new taxon is a member of the Lasiograptinae, and is closely allied to the aforementioned species.

The thecae of B. quadrithecatus exhibit striking similarity with Dicaulograptus hystrix (Bulman). However, both the details of thecal construction and primordial astogeny differ markedly between these species. The thecal similarities appear to be convergent. Accordingly, D. hystrix is probably not closely allied to the Lasiograptinae.

A new argyrolagoid marsupial, Hondalagus altiplanensis n. gen., n. sp., from the middle Miocene (Santacrucian–Friasian) age locality of Quebrada Honda in southernmost Bolivia represents the smallest and most specialized member of the family Argyrolagidae known. The lower molars are hypselodont and lack vertical grooves labially and lingually, and M4 is greatly reduced relative to M3. In overall size and structure, H. altiplanensis compares best with Microtragulus catamarcensis (Kraglievich, 1931) from rocks of late Miocene (Huayquerian) age in northwest Argentina. Hondalagus altiplanensis demonstrates that the adaptive radiation of argyrolagoids was much greater than previously envisioned, and that generic differentiation of known taxa occurred no later than early–middle Miocene time in South America.

Paramys compressidens Peterson, from the Uintan of Utah, has long been considered a member of the genus Ischyrotomus Matthew. A re-examination of the type and referred specimens of this species demonstrates that it does indeed belong in the genus Paramys and that several of the previously cited referred specimens can be allocated to other known species.

Systematic relationships between the species of Paramys are analyzed. Recognizable morphoclines within this genus are increase in size and amount of crenulation of the enamel on the cheek teeth, and changes in the cross-sectional shape of the lower incisor. Several species previously considered as belonging to Paramys (P. simpsoni Korth, P. savagei Michaux, P. pourcyensis Michaux, P. ageiensis Michaux) may be referable elsewhere.

Thisbemys Wood, Leptotomus Matthew, and Tapomys Wilson can be directly derived from the known species of Paramys. The origin of several other genera may possibly be found within Paramys, but no ancestral morphotype is currently known.

Recently Ellis L. Yochelson visited the Shanghai Museum of Natural History and saw the illustrated specimen of Dentalium (A.) acumen from the lower Carboniferous of Guizhou Province, China. He pointed out that the straight shell of Dentalium (Antalis) acumen (Koninck) which was described by Wang (1987) is an orthoconic cephalopod. The anterior part of the shell is crushed, as is common on the living chamber of those orthocones which preserve it. Examination of the early part of the shell showed that it was broken along a curved surface; that is, it broke along a septal wall. By wetting this area, it was possible to see the outline of a central siphuncle at this septum. Thus, it remains true that until now, no scaphopod has been recorded in Chinese Paleozoic beds.

With the quest for more detailed and precise micropaleontologic data has come a stronger emphasis for quantitative studies of microfossils. Many workers have realized, however, that slide preparation and counting can contribute large errors in quantitative studies (Battarbee, 1973; Moore, 1973; Hattner and Wise, 1980; Laws, 1983).

Recent advances in microcomputer technology have created many tools for image processing and analysis that are useful for paleontologic studies. Although the Journal of Paleontology is not the appropriate forum for reviews of products from the rapidly changing field of computer technologies, a brief introduction to techniques presently available for image processing and analysis, and their potential applications to the field, may be of value to paleontologists.

A large-diameter coring device was designed to recover plant litter in fluvial sediments as part of a taphonomic study of plant deposition in a modern river system. The corer was used to retrieve unconsolidated sediments from shallow (< 1.5 m) water, either from a boat or from the riverbank, and was designed to be transportable for use in remote reaches of tropical rivers. The device is operable by a single person, easily repaired, and rugged.

H. C. Lea (1843, 1846), in papers on molluscs from the Tertiary of Virginia, described and illustrated the scutum and carina of a scalpellid barnacle, which he mistakenly identified as two new species of molluscs. The scutum was described as Avicula multangulata (after 1843 as A. multangula) and the carina as Patella acinaces. Conrad (1863), Meek (1864), d'Orbigny (1852), and Heilprin (1884) listed these species in their enumerations of the Tertiary molluscan fauna. Meyer (1888, p. 138) was the first to recognize the cirriped nature of these fossils. He correctly identified the plates as scutum and carina, assigned them to Scalpellum magnum Darwin, 1851, an English Pliocene species, and provided detailed figures of the type specimens from the collection of the Academy of Natural Sciences of Philadelphia (Meyer, 1888, figs. 11, 12a).