Some of the relatively recent literature correlating morphological variation in benthic foraminifera with environmental parameters such as temperature, salinity, carbonate solubility, depth, nutrition, substrate, dissolved oxygen, illumination, pollution, water motion, trace elements, and rapid environmental fluctuation is reviewed. It appears some variables (most notably depth) are recorded more frequently, which may affect some conclusions. Although each variable is treated separately, it appears that almost no variables act independently on test morphologies. In reviewing the literature, it becomes clear that there are many individual trends, especially with shell ornamentation, but few broad ones, and that it is almost impossible, with exception of some of the larger reef-dwelling, symbiont-bearing foraminifera, to predict how any species will react to various parameters. The broad trends concern thinning or thickening of carbonate tests with changing carbonate availability, temperature, and salinity. It appears that many observations of morphological changes within species may not be recorded in the literature, perhaps because authors did not recognize the importance of small details that would be of importance at a later time.

Specimens of the discoid, chambered megafossil Kullingia delicata (Fedonkin) occur near the base of member 2 of the Chapel Island Formation on the Burin Peninsula of Newfoundland. Morphologic and taphonomic features suggest that these fossils can be interpreted as the impressions of pelagic chondrophorines. Kullingia provides a link between Ediacaran and Paleozoic forms, and thus supports the view that the Chondrophorina represents a conservative evolutionary lineage extending back into the Precambrian.

The upper surface of the corallum of Catenipora rubra was often at or just above the sediment-water interface during life. The vertical growth rate was barely sufficient to keep pace with background sedimentation and possible subsidence of the corallum. Therefore, the colonies were in constant danger of being covered by influxes of sediment, especially during storms. This was compensated by the ability of polyps to respond to sedimentation events and by certain aspects of colony growth. Rapid regeneration following partial mortality involved budding of uninjured polyps and rejuvenation of damaged individuals, in some cases accompanied by a type of axial increase not previously known in tabulate corals. Rapid lateral expansion was possible because small, “immature” polyps could bud and grow in a reptant manner.

Interconnected ranks of the cateniform corallum served to dam shifting sediment at the periphery of the colony. Lacunae within the colony were reservoirs for material that breached peripheral ranks and for sediment that settled on the ranks and was rejected by polyps or removed by passive flow. Polyps comprising the colony were distributed over a large area of the substrate surface, thereby decreasing the probability of complete mortality during sedimentation events and increasing the probability that a sufficient number of individuals would survive to ensure optimum regeneration. The corallum, anchored in the substrate and with sediment filling the lacunae, provided a broad, stable base during high-energy events.

It remains to be established how widespread these growth patterns and strategies were among other corals with cateniform colonies, a form that appeared in many unrelated stocks. Most previous workers emphasized physical strength when considering functional morphology, following a tacit assumption that the corallum rose high above the substrate and was therefore susceptible to breakage during high-energy events. An understanding of the origin of cateniform patterns and the phylogeny of these corals requires knowledge of their modes of growth and life-history strategies, which were genetically as well as environmentally controlled.

The Bromide Formation of the Middle Ordovician Simpson Group of Oklahoma contains one of the oldest diverse bryozoan faunas in North America. The early divergence of many trepostome clades is revealed in these rocks. Three trepostome bryozoan species belonging to family Halloporidae are described from this fauna. Discriminant analysis is used to define the following halloporid species: Diplotrypa schindeli n. sp., Tarphophragma karklinsi n. sp., and Tarphophragma macrostoma (Loeblich). Preliminary cladistic analysis indicates that the family Halloporidae was already a distinct lineage by the Middle Ordovician. This suggests that by this time, many of the major trepostome clades were already established.

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.

Mytiloides hattini, a new species of inoceramid bivalve from the basal Turonian (Upper Cretaceous), is described and its stratigraphic importance discussed. This inoceramid is particularly significant because its first occurrence can be used as a marker for the base of the Turonian in strata that typically contain no ammonites and few other taxa. The lowest occurrence of Mytiloides hattini is characterized by abundant specimens over wide regions of the Western Interior of North America; this species also apparently occurs in the lowest Turonian strata of western Europe. The typical absence of ammonites in this stratigraphic interval potentially makes the first occurrence of Mytiloides hattini an important fossil for regional and intercontinental correlation of the Cenomanian–Turonian boundary.

The gastropod Drepanochilus pervetus (Stanton) and the bivalve Cytrodaria rutupiensis (Morris) occur in the Mount Moore Formation at Strathcona Fiord, west-central Ellesmere Island, northern Canada. They are the first marine mollusks identified from the Eureka Sound Group of the Canadian arctic islands. These mollusks correlate with Paleocene faunas of the Cannonball Formation of North Dakota and South Dakota, the Prince Creek Formation of northern Alaska, the Barentsburg Formation of Svalbard, and the Thanet and Oldhaven Formations of southeastern England. These occurrences imply that the earliest Tertiary Arctic Ocean molluscan fauna was compositionally distinct from coeval faunas of the northern Atlantic Ocean.

A revision of the Silurian paulinitid scolecodont taxa from the Power Glen Formation of the Medina Group at Niagara Gorge relies on multi-element taxonomy to place the five genera and ten species of Eller (1940) into just two species: Kettnerites invisibilis (Eller, 1940) and ?K. plenidens (Eller, 1940). The generic name Nereidavus should not be used for paulinitids; the type specimen of Nereidavus has been lost, and indications are that it was probably not a paulinitid.

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.

The capitulum and peduncular armature of Arcoscalpellum toulmini Weisbord are described on new material from the lower unnamed member of the Porters Creek Formation in Wilcox County, Alabama. A few scuta and a possible tergum of a species Zeugmatolepas Withers bearing considerable resemblance to Z. cretae (Steenstrup) were recovered from the same locality.

The coral-inhabiting archaeobalanid barnacle genus Eoceratoconcha Newman and Ladd, 1974, previously known only from the middle Miocene of Trinidad and questionably from the lower Miocene of Jamaica, is represented by a new species, E. weisbordi, in the coral Solenastrea bournoni Milne-Edwards and Haime from the upper Pliocene Pinecrest beds of Sarasota County, Florida. The new species differs from Miocene species of Eoceratoconcha in its larger overall size and more subdued wall plate ribbing, and is further distinguished from the type species, E. kugleri Newman and Ladd, in having a well-developed scutal adductor ridge and conspicuous tergal depressor muscle crests. The opercular morphology of E. weisbordi further supports the proposal of Newman and Ladd (1974) that Eoceratoconcha is ancestral to the pyrgomatid genus Ceratoconcha Kramberger-Gorjanovic.

The vincular furrow morphology of 19 species of Phacopidae is critically examined. The anterior part of the vincular furrow is much less variable than the posterior part of the vincular furrow, but it can be absent, shallow, deep, or have a slightly ventrally elongated boss. The posterior part of the vincular furrow can have pleurovincular pits (for reception of the thoracic pleural tip processes) or indentations for these processes, plus bounding walls that are variably indented laterally and very variable in vertical elongation. The functional morphology of the various elements of the vincular furrow is best explained by a paradigm of resistance to lateral shearing.

All elements of the vincular furrow in Devonian taxa had already appeared in the Early Silurian, but Early Silurian taxa are richer in diversity of elements. Some Devonian subspecies, essentially based on dorsal morphologies, show distinctly different vincular furrows. Cluster analysis of the data gathered on the vincular furrow complexes regroups the distinctly different Devonian subspecies and some Silurian subgenera. Other vincular furrows within the Phacopidae suggest that Reedops is near the Phacops logani complex and that the Phacopidellinae is a valid subfamily, but formal emendations within the family are not suggested because of incomplete data, notably on our knowledge of the distribution of vincular furrows. The use of the widely conceived genus Phacops Emmrich, 1839, over more recently described taxa such as Paciphacops Maximova, 1972, is presently favored, as this reflects more clearly current understanding of the systematics within the family Phacopidae.

Primary types of the North American taxa Phacops cristata, P. cristata gaspensis, and Acernaspis (Acernaspis) orestes are critically reviewed; significant changes of previous interpretations are suggested. Phacops cristata vitrea n. subsp. is erected. Thoracic pleural tip processes and anterolateral ventral pygidial processes are described in detail within Phacops rana rana and Acernaspis (Acernaspis) orestes. A pathological specimen of Phacops rana rana, with an injured eye, demonstrates that the individual did not revert to a primitive type of lens packing.

The hypostome of Glyptambon Holloway, 1981, provides additional morphological evidence that this genus is more closely related to the Siluro-Devonian subfamily Dalmanitinae than to Ordovician “Mucronaspidinae.” New species of Glyptambon are G. amsdeni n. sp., from the Ludlow Brownsport Formation in west-central Tennessee, and G. gassi n. sp., from late Wenlock strata of the Racine Formation in Illinois.

An almost complete specimen of the pentacrinid Seirocrinus subangularis (Miller, 1821) is described from the Red Deer Member of the Fernie Formation in the Rocky Mountains of central-western Alberta. Associated ammonites representing the Stokesi Subzone of the Margaritatus Zone indicate a Late Pliensbachian (Early Jurassic) age for the specimen. Taphonomic features suggest preservation in soft muds on a quiet, oxygen-deficient seafloor, so that the lower surface is preserved intact while ossicles on the exposed upper surface became disarticulated and were slightly disturbed. This occurrence in western Canada represents a major extension of the geographic range of the species.

New material of the poraspid Alainaspis platyrhina Elliott and Dineley has made it possible to provide a more extensive reconstruction of this animal. It is now clear that an elongated branchial opening was present below the lateral lamina and that a well-developed post-branchial lobe was present. No branchial plate has been identified and this may have been fused to the dorsal shield, forming the ventral lamina. The lateral lamina is now seen to terminate in a rounded angle before the posterior margin of the shield. Several ventral shields with similar ornament are identified as belonging to A. platyrhina. These are broad and deep and are consistent with the original interpretation of this animal as a filter feeder. One similar shield with a coarser ornament is tentatively assigned to the closely related species Boothiaspis ovata Broad.

Utaherpeton franklini n. gen. and sp., from the Manning Canyon Shale Formation of Utah, is the oldest known microsaur. The horizon is dated as equivalent to the lowermost Namurian B of Europe (transitional from Upper Mississippian into lowermost Pennsylvanian in North American terminology) on the basis of a rich assemblage of fossil plants. The specimen may be tentatively placed within the suborder Microbrachomorpha. It exhibits the primitive character state for many microsaur features, but no synapomorphies are recognized that support a specific sister-group relationship between microsaurs and any other group of Paleozoic tetrapods.

A new species of the fern Phlebopteris, P. tracyi n. sp., is described from the Jurassic Coon Hollow Formation in the Wallowa terrane in the Snake River Canyon, Oregon and Idaho. The leaf is as large or larger than all specimens of previously described species of Phlebopteris. The pinnae of the new species are divided into many widely spaced, narrow, elongate pinnules that have obtusely pointed apices. Each pinnule contains a strong midrib from which lateral veins arise at a high angle and give off anastomosing branch veins. The fertile pinnae bear circular superficial sori arranged in a single row on each side of midrib. The new Phlebopteris occurs beneath a horizon containing marine fossils of Middle Jurassic age. The presence of P. tracyi in the Coon Hollow Formation indicates that it was deposited under a humid, warm to hot climate.