Thanks to the Linnaean system of Biological Nomenclature systematics these days is an ordered discipline. Debates over specifics still abound, but there is little argument that taxonomy should reflect the current state of our phylogenetic knowledge. However, recent proposals to replace the historically developed and universally utilized Linnaean system of Biological Nomenclature with an alternative “phylogenetic” system of nomenclature (PN; formulated as the draft PhyloCode [http://www.ohiou.edu/phylocode]; e.g., Cantino and de Queiroz, 2000; see Nixon and Carpenter, 2000 for exhaustive citations) are flawed because they are founded on the misconception that Linnaean classification cannot (and therefore currently does not) accurately represent phylogeny. This is not the case—the ranked Linnaean system is a hierarchy, but then again, so is a cladogram and hence the former can mirror the latter. Although implementation of the proposed PhyloCode would result in huge implications within biological systematics in general (Nixon and Carpenter, 2000; Forey, 2001; Schuh, submitted), some workers (e.g., Brochu and Sumrail, 2001) have argued that proposals to implement this new system of “phylogenetic” nomenclature are a “good thing” for paleontology in particular. Since viewpoints contrary to the PhyloCode have already been aired elsewhere (e.g., Dominguez and Wheeler, 1997; Moore, 1998; Benton, 2000; Nixon and Carpenter, 2000; Forey, 2001), my aim here is to highlight a few areas of PN that make it an especially problematic proposal for paleontologists.

A unique radiolarian fauna recovered from the top part of the Changxingian stage in south Guizhou, Southwest China, includes at least nineteen species one of which is new. The fauna is mainly composed of Permian species extensively distributed all over the world, such as Hegleria mammilla (Sheng and Wang, 1985); Ishigaum trifustis De Wever and Caridroit, 1984; Foremanhelena triangula De Wever and Caridroit, 1984; Triplanospongos dekkaensis (Noble and Renne, 1990); Nazarovella gracilis De Wever and Caridroit, 1984; and Nazarovella inflata Sashida and Tonishi, 1986, among others. Besides these species, a new radiolarian assemblage, represented by Copicyntra ziyunensis new species; Copiellintra fontainei (Sashida, 2000); Klaengspongus spinosus Sashida, 2000; and Paroertlispongus? sp., was discovered in South China. The assemblage only occurs in less than 10 m siliceous rock strata under the Permian-Triassic boundary at south Guizhou, Guangxi, and north Sichuan. Although only a few new species appeared during this period, they are very important for understanding both the radiolarian extinction at the end of the Permian and the relation between the Paleozoic and Mesozoic Radiolaria.

The reticuloceratid ammonoid Arkanites relictus (Quinn, McCaleb, and Webb, 1962) is represented by hundreds to thousands of individuals from horizons isolated both stratigraphically and geographically in northern Arkansas. These assemblages appear to represent mass mortality events resulting from a semelparous reproductive strategy. Arkanites relictus occurs as a dimorphic pair (depressed, widely umbilicate, cadiconic conchs and compressed, narrowly umbilicate, pachyconic conchs) thought to reflect sexual dimorphism. Late stage ontogenetic modifications, such as septal crowding and change in aperture profile, are widely cited evidence of sexual maturity in ammonoids. Septal crowding begins at a predictable ontogenetic stage in the compressed forms of A. relictus, but specimens with cadiconic conchs do not have crowded septa even at the largest diameters available.

Depending on the trait examined and the proxy for age of individuals, the dimorphism in Arkanites relictus (using the depressed form as the reference morph) is the result of acceleration, neoteny, or hypermorphosis plus neoteny. If size (diameter) is considered a proxy for age, the dimorphs were the same age at death, and the septa in the compressed variants developed via acceleration relative to the depressed variants. Regarding conch shape (width vs. diameter), the compressed morphs developed via neoteny relative to the depressed morphs. If septal count is considered a proxy for age, the dimorphs were not the same age at death, and the compressed forms were produced by a combination of hypermorphosis plus neoteny, i.e., they grew longer yet slower than the depressed forms. In A. relictus, the heterochronic processes of hypermorphosis and neoteny may have been operating simultaneously, which is an interesting possibility because it is an example of a combination of both peramorphic and paedomorphic processes.

The Fossil Brook Member of the upper Chamberlain's Brook Formation is a thin (up to 14 m) but distinctive, unconformity-bound depositional sequence recognizable from Rhode Island to eastern Newfoundland in Avalonian North America. Its diverse trilobite fauna was first described more than century ago from the limestone-rich facies of the member in southern New Brunswick. However, the systematics, stratigraphic context, and biostratigraphic significance of these trilobites have remained poorly known. A revision of the conocoryphid and paradoxidid trilobites has been completed, and the taxa set into their stratigraphic context within the middle Middle Cambrian. The faunas of the Fossil Brook are assigned to the Eccaparadoxides eteminicus Zone of Avalon. Although biogeographic barriers between Avalon and Gondwana remained strong in the Middle Cambrian and few shared trilobite species are present, a generalized correlation of the E. eteminicus Zone into Gondwana is with the Badulesia tenera Zone of the Toushamian Stage in Morocco and the Badulesia Zone of the Caesaraugustian Stage in Spain.

A new glyptocystitidoid rhombiferan, Cheirocystis fultonensis, is described from the contact zone between the Point Pleasant Formation and lower Kope Formation exposed 50 km south east of Cincinnati, Ohio. This species, the second known glyptocystitidoid rhombiferan from the Cincinnatian Series and the youngest known species of Cheirocystis, shows significant suture modification where pectinirhombs are placed. Growth of large pectinirhombs along vertical sutures results in an unusual bowing-out of thecal plate sutures that is also seen in the related species Cheirocystis anatiformis. A juvenile specimen shows that ontogenetically the lateral shared ambulacra become less pronounced, pectinirhombs are added until the eight standard positions are expressed, and the periproct becomes proportionately smaller with age.

Aetosaur fossils from the Upper Triassic Ischigualasto Formation of Argentina formerly assigned to Aetosauroides scagliai Casamiquela and Argentinosuchus bonapartei Casamiquela are reassigned to Stagonolepis robertsoni Agassiz (small specimens) and S. wellesi (Long and Ballew) (larger specimens). Numerous features of the skull, vertebral column, appendicular skeleton, and particularly the armor, of these Argentinian aetosaurs are identical to those of Stagonolepis and differ from other aetosaurs. Identification of Stagonolepis in South America has important implications for the correlation of nonmarine strata across Late Triassic Pangea. Stagonolepis is an index taxon of the Adamanian land-vertebrate faunachron of latest Carnian age. Its occurrences in the Ischigualasto and Santa Maria formations, as well as at the type locality in the Lossiemouth Sandstone of Scotland and in the Blasensandstein of the German Keuper, cross-correlate with a well-established tetrapod biostratigraphy of the Chinle Group in western North America. Thus, all Stagonolepis records are of Adamanian (latest Carnian) age, not Otischalkian (early or “middle” Carnian) age, as proposed by some earlier workers. This correlation also demonstrates that the oldest known dinosaurs are not from the Ischigualasto and Santa Maria formations. Previous workers obtained radioisotopic dates of 227.8 Ma from the Ischigualasto Formation, providing a maximum numerical date for Stagonolepis-bearing units. This date must be late Carnian, not of Ladinian age, and thus supports the apparent age of the Ladinian-Carnian boundary (232 Ma) of time scales based on the Newark Supergroup in eastern North America.

Re-examination of the dentitions of carpolestid plesiadapiform mammals from the late Paleocene Swan Hills locality, northern Alberta, and correlative localities in the vicinity of Roche Percée, southeastern Saskatchewan, Canada, indicates that Carpodaptes cygneus (Russell) as known from these sites is polyphyletic: the name C. cygneus is here restricted to the Swan Hills carpolestid, while the Roche Percée form represents a new, more derived species, Carpodaptes stonleyi. Other purported records of C. cygneus are reconsidered as well: C. cygneus from DW-1, central Alberta, is more appropriately dubbed C. cf. cygneus; C. cygneus at Canyon Ski Quarry, central Alberta, is best identified as C. cf. stonleyi, while C. cf. cygneus from Police Point, southeastern Alberta, has closest affinities to C. hazelae Simpson. Carpolestids from the Tongue River Formation, North Dakota, are referred to Carpodaptes cf. hobackensis Dorr and C. cf. hazelae. After a review of the available evidence, the recent hypothesis that C. cygneus and other North American carpolestids are congeneric with Carpocristes oriens Beard and Wang from the Paleocene or Eocene of China, is rejected.

The ichnogenus Pholeus Fiege, 1944, is a common constituent of the Lower Muschelkalk (Middle Triassic) carbonates of the Germanic Basin, where it occurs in the upper part of shallowing upward cycles. It is restricted to a marly limestone lithofacies and is commonly associated with omission and erosion surfaces. The dwelling structures (domichnia) were created in a shallow-marine to lagoonal paleoenvironment in an intertidal to shallow subtidal setting. New material from Thuringia and Lower Saxony makes a reevaluation of Pholeus possible and confirms the validity of this ichnogenus. Certain features, such as general form, wall, lining, and branching differentiate it from similar trace fossils. In addition to the already described P. abomasoformis, three new ichnospecies are named for distinctive forms: P. bifurcatus, P. platiformis, and P. elongatus. Based on geometry, size, and wall lining, the burrow producers were most probably decapod crustaceans. Many similarities to modern burrows of Callianassa sp., Neocallichirus grandimina, and Nephrops norvegicus suggest thalassinian shrimps and lobsters as likely tracemakers of Pholeus burrows. Compound burrow systems and retrusive burrow parts with spreiten-like structures are common and point to an upward shifting of the burrows related to certain sediment input in relation to tidal currents.

Psilonichnus lutimuratus n. ichnosp. is described from a Pliocene estuarine-mouth depositional environment (Skolithos ichnofacies) of the Olympic Peninsula, Washington, U.S.A. These simple Y-, I-, and J-shaped, mud-lined burrows occur in situ as dense patches within alternating, wavy-bedded sandstone and mudstone in a storm and flood influenced coastal sequence from an active tectonic margin. The I- and J-shaped traces represent erosional modification of burrow tops during storm-flood events. The new ichnospecies differs from the two other Psilonichnus ichnospecies by the distinct mud-lining of the burrow wall. Comparison with living thalassinoidean shrimp burrows and shrimp ecology allow this new ichnospecies to be attributed to the extant mud shrimp Upogebia. Biological and behavioral characteristics of this living shrimp restrict it to the mouth of the open estuary, and these parameters can be used to narrowly define a shoreline environment in the stratigraphic record.

Sphenothallus Hall, 1847 is a widespread Paleozoic marine taxon that has been interpreted most recently as a tubiculous annelid or other ‘worm’ or as a thecate hydrozoan or scyphozoan cnidarian (e.g., Mason and Yochelson, 1985; Feldmann et al., 1986; Van Iten et al., 1992, 1996; Neal and Hannibal, 2000; Zhu et al., 2000). Members of this genus are characterized by a very gently tapered, finely lamellar apatitic tube bearing a closed subconical holdfast and a pair of robust longitudinal thickenings situated at the ends of the tube's greatest diameter (Zhu et al., 2000). Rarely, the tube exhibits an internal transverse wall that extends adaperturally along the inner surface of the tube proper and may also exhibit a subcylindrical terminal protuberance (Van Iten et al., 1992, figs. 5, 6). The transverse wall of Sphenothallus is essentially identical in gross morphology and microstructure to the schott (apical wall) of conulariids, an extinct group of thecate cnidarians (Van Iten, 1991, 1992a, 1992b; Jerre, 1994; Van Iten et al., 1996; Hughes et al., 2000) that may have been closely related to Sphenothallus (Van Iten et al., 1992). Clarke (1913, pl. 26, figs. 16-18; see also Van Iten et al., 1992, fig. 3) illustrated a compound specimen of S. sica consisting of numerous “daughter” tubes arranged in a highly regular manner (in opposition and evenly spaced) along a single, relatively large “parent” tube whose test wall appears to be confluent with the base of the “daughter” tubes. This compound specimen is distinctly different from the more common associations of epibiontic, holdfast-bearing Sphenothallus arranged in a less orderly fashion on Sphenothallus tubes or other shells (see for example Feldmann et al., 1986, fig. 2), and probably is best interpreted as a clonal colony. Sphenothallus tubes, both solitary and branched, are most similar to thecae of solitary and colonial hydrozoan and scyphozoan polyps, differing from these relatively delicate structures mainly in being mineralized and in bearing a pair of longitudinal thickenings. Like conulariids, Sphenothallus occurs in rocks originally deposited in a broad spectrum of marine facies (open carbonate shelf to restricted shale basin), but is perhaps most conspicuous in restricted basin and shelf slope facies represented by dark shales and lime mudstones.

The late Albian marine fossil record from eastern Australia derives from the sedimentary succession of the Great Artesian Basin deposited in a vast epicontinental sea which then covered much of the continent (see Frakes et al., 1987). Ammonites of this age are common but their generic diversity is low. Heteromorph assemblages almost exclusively comprise the taxa Myloceras, Labeceras sensu stricto and Labeceras (Appurdiceras) of the Family Labeceratidae that were widely distributed in higher latitudes of the Southern Hemisphere during Late Albian time (see Aguirre Urreta and Riccardi, 1988; Klinger, 1989). Some 19 endemic species of these genera are recorded from the Great Artesian Basin in the present literature (Etheridge, 1892; Whitehouse, 1926; Reyment, 1964) and there are additional undescribed species (Henderson and McKenzie, unpublished data). The Australian Late Albian epicontinental sea was clearly a site of significant speciation for Labeceras and Myloceras and it has been argued that the Great Artesian Basin represents the evolutionary center for these genera (Henderson, 1990).

Representatives of the Prodromitidae are characterized by relatively large (up to 150 mm diameter) lenticular conchs with acute ventral keels and complex multilobate sutural configurations. The systematic position of the Prodromitidae has been the subject of considerable speculation (see Work et al., 1988 for review). The nominate genus, Prodromites Smith and Weller, 1901 (type species, Goniatites gorbyi Miller, 1891), is not typical and represents the culmination of the lineage, showing characters which have led authors to refer it to both the Gephuroceratina (Ruzhencev, 1960, 1962, 1965; Bogoslovsky, 1969; Ruzhencev and Bogoslovskaya, 1978) and the Prolecanitina (Miller and Collinson, 1951; Weyer, 1972; Furnish and Manger, 1973; Kullmann, 1981; Bartzsch and Weyer, 1988; Kullmann et al., 1991). Discovery of an ancestral prodromitid genus, Eoprodromites Work, Mapes, and Thompson, 1988 (type species, E. kinderhooki), in the Hannibal Shale of northeastern Missouri provided clarification on the derivation of Prodromites and provided a link to yet a third enigmatic genus, Qiannanites Ruan, 1981 (type species, Q. acutus). Work et al. (1988) concluded that the Prodromitidae were prolecanitid offshoots that appeared in the early Tournaisian with Qiannanites, progressed through Eoprodromites, and climaxed with Prodromites early in the late Tournaisian. Although aspects of sutural ontogenesis, conch morphology, and stratigraphic distribution unite these genera, subsequently obtained specimens of Eoprodromites kinderhooki provide additional sutural and morphological details (Figs. 1, 2) that support derivation from the prionoceratacean subfamily Pseudarietitinae Bartzsch and Weyer, 1987, as more recently suggested by Becker (1993a, p. 471).

The Callapoid family Necrocarcinidae Förster, 1968, was a successful group of crabs distributed worldwide and ranging in age from the Early Cretaceous to the Oligocene. Included taxa appear to have preferred littoral to sublittoral environments (e.g., Fraaye, 1994), have crawled closely appressed to the bottom and/or to have sheltered in muddy bottoms (Bishop and Williams, 1991), and probably were adapted to temperate to tropical climatic settings (Schweitzer and Feldmann, 2000). This lifestyle is similar to that of extant calappids. Before the present study only two calappids were known from the Maastrichtian type area. Both these species, Prehepatus werneri Fraaye and Collins, 1987, and Paranecrocarcinus quadriscissus (Noetling, 1881), have been described and discussed in detail by Collins et al. (1995).

The Echinoderm fauna of the Brassfield Formation (Lower Silurian, Early to Middle Llandoverian) contains more than 30 species and is locally common in southern Ohio making it one of the most important Early Silurian faunas known (Foerste, 1919, 1936; Ausich, 1984a, 1984b, 1985, 1986a, 1986b, 1986c, 1987; Ausich and Schumacher, 1984; Ausich and Dravage, 1988). At present, the Brassfield Formation has produced two callocystitid rhombiferans including Brockocystis nodosarius Foerste (1919) and Anartiocystis foerstei Ausich and Schumacker (1984). Neither of these taxa is well-known, being described from a handful of moderately well to poorly preserved specimens each. The discovery of Anartiocystis whitei n. sp., the third callocystitid species known from the Brassfield Formation and second known species of the genus, greatly clarifies the morphology of the genus adding significant information on the plating of the ambulacra and stem.

Graptolites are relatively uncommon fossils in the Middle and Upper Ordovician carbonates of the North American mid-continent. With the notable exception of the Viola Springs Formation in Oklahoma, most units contain a single species, which occur within narrow stratigraphic intervals (often single beds). While uninteresting in terms of their diversity, these monospecific collections commonly yield excellent three-dimensionally preserved specimens that can be isolated from their matrix and studied. In particular, the large number of well-preserved specimens allows for accurate evaluations of intra-specific variation and reliable descriptions of taxa that are generally known from flattened or otherwise distorted material. Additionally, these graptolite collections can provide important biostratigraphic ties between disparate facies—shallow mid-continental limestones and the deeper-water black shales characteristic of continental margins.

Werdelin and Lewis (2000) recently described a new species of the saber-tooth genus Megantereon (Mammalia, Carnivora, Felidae) from Late Pliocene (∼3.5 Ma) deposits of the Nachukui Formation south of the Turkwel River in Turkana, northern Kenya (Ward et al., 1999). The new species, Megantereon ekidoit, is said to represent the earliest occurrence of this genus in Africa. It was described from a right mandibular ramus (KNM-St 23812) with i3–ml. As discussed below, the post-canine diastema is longer than the cheek-tooth row, since there does not appear to have been a third premolar (p3), and the coronoid process is relatively well developed, showing a hook-shaped morphology (Werdelin and Lewis, 2000: Fig. 1). The fourth premolar (p4) and the lower carnassial tooth (ml) show considerable wear.

Palmqvist (2002) has criticized our attribution of the mandibular ramus of Megantereon from South Turkwel, Turkana Basin, Kenya, to a new species, M. ekidoit (Werdelin and Lewis, 2000), suggesting instead that it “unequivocally” belongs to the African species M. whitei. We believe that this criticism stems from a misunderstanding of our statements and from an erroneous view of variability within Megantereon. In this reply we shall address Palmqvist's criticisms, showing that M. ekidoit is not synonymous with M. whitei, and also that the specific attribution of various Megantereon specimens is not as clear cut as Palmqvist (2002; Martinez Navarro and Palmqvist, 1995, 1996) believes.