The late history of edrioasteroids has come to light only in the last 40 yr. When the edrioasteroid chapter of the Treatise on Invertebrate Paleontology was published (Regnéll, 1966) the youngest known edrioasteroids were upper Mississippian (Chesterian). Since that time, a series of papers have described edrioasteroids in the Pennsylvanian (Fraunfelter and Utgaard, 1970; Bell, 1976; Sumrall, 1992; Sumrall and Bowsher, 1996; Sumrall et al, 2000, 2006). Pennsylvanian edrioasteroids now include nine species distributed among six genera, including one fauna bearing four genera (Sumrall et al., 2006). These edrioasteroids are not limited to a single clade but include postibullinids, plesiomorphic agelacrinitids, and derived clavate discocystinids.

The systematic position of taxa from the work of Gerard Troost has been confused and many have not been properly credited. Complete synonymy listings of Troost names indicate that the author and date of many names need revision, including several taxa that can finally be credited to Troost.

In 2006, we (Grande & Hilton, 2006) described a well-preserved fossil sturgeon (Acipenseridae) from the Late Cretaceous of Montana and proposed the name †Psammorhynchus longipinnis Grande & Hilton for the new species. Through accidental discovery of an on-line taxonomic database of flatworms (Tyler et al., 2006) and subsequent investigation, we recently discovered that the genus-group name is preoccupied by Psammorhynchus Meixner, 1938 in Platyhelminthes (“Turbellaria”). Therefore, under Article 60 of the International Code of Zoological Nomenclature (ICZN, 1999), a replacement name is required for the junior homonym †Psammorhynchus Grande and Hilton.

Class Hyolitha Marek, 1963 encompassing the Order Hyolithida Sysoev, 1957 (Early Cambrian to Upper Permian) and Order Orthothecida Marek, 1966 (Early Cambrian to Early Devonian) consists of a group of conical, calcareous-shelled invertebrates of controversial affinity. One opponent view holds that hyoliths may be reasonably accommodated under the Phylum Mollusca (Malinky and Yochelson, 2007 and references therein), whereas another supports separate phylum status under the name Hyolitha (Pojeta, 1987 and references therein). Hyolith abundance and diversity attain a maximum in the Cambrian, followed by a progressive decline up to their Permian extinction (Fisher, 1962; Wills, 1993). Their demise was part of the extinction event of the Late PermianlEarly Triassic. The cause(s) of this event remains controversial (Erwin et al., 2002), and no imprint remains in the geologic record of the specific circumstances surrounding the disappearance of the hyoliths, though it is highly probable that reduced population size was a contributing factor. Given the overall rarity of Late Paleozoic hyoliths, every occurrence is worthy of note to better understand patterns of hyolith diversity and abundance in the Late Paleozoic, the geographic and stratigraphic distribution of hyolith taxa and circumstances related to their extinction. The species from the Upper Permian described herein is among the youngest, if not the youngest, members of class Hyolitha.

During the Cenozoic, the New World tropics supported a rich biodiversity of mammals. However, because of the dense vegetative ground cover, today relatively little is known about extinct mammals from this region (MacFadden, 2006a). in an exception to this generalization, fossil vertebrates have been collected since the second half of the twentieth century from Neogene exposures along the Panama Canal. Whitmore and Stewart (1965) briefly reported on the extinct land mammals collected from the Miocene Cucaracha Formation that crops out in the Gaillard Cut along the southern reaches of the Canal. MacFadden (2006b) formally described this assemblage, referred to as the Gaillard Cut Local Fauna (L.F., e.g., Tedford et al., 2004), which consists of at least 10 species of carnivores, artiodactyls (also see recent addition of peccary in Kirby et al., 2008), perissodactyls, and as described by Slaughter (1981), rodents. Prior to the current report, the horses (Family Equidae) from the Gaillard Cut L.F. consisted of only four fragmentary specimens including: two isolated teeth, i.e., one each of Archaeohippus sp. Gidley, 1906 and Anchitherium clarencei Simpson, 1932; a heavily worn partial dentition with p2-p4 of A. clarenci; and a partial calcaneum of Archaeohippus. Although meager, these fossils appear to represent two distinct taxa of three-toed horses otherwise know from the middle Miocene of North America, i.e., the dwarf-horse Archaeohippus sp. and the larger Anchitherium clarencei.

The order Mecoptera is represented on all continents, albeit with an uneven distribution. Mecoptera includes about 34 families (Labandeira, 1994, p. 34), only four of them, until now, represented in South America: Permochoristidae Tillyard, 1917 (†) (Pinto, 1972); Bittacidae Handlirsch, 1906 [and stem-group “Neorthophlebinae” (†)] (Petrulevičius, 2001a, 2003, 2007); Nannochoristidae Tillyard, 1917; and Eomeropidae Cockerell, 1909. The two latter families have a present relict distribution in southern South America but without fossil record, obviously an artifact due to few studies of fossil insects in the subcontinent. The diversity of recent Bittacidae is high in South America with respect to other continents. Thirty-five percent of recent genera of Bittacidae come from South America, and 80% of these genera are endemic (extracted from Penny, 1997). Bittacidae is well represented in the fossil record, with species from the Jurassic of Patagonia (Petrulevičius, 2007), Lower Cretaceous of Brazil (Petrulevičius and Martins-Neto, 2001), to the late Paleocene of Argentina (Petrulevičius, 1998, 1999, 2001b, 2003). This contribution reports a specimen belonging to the Panorpoidea, a group with no recent species in South America and very few species in the entire Southern Hemisphere.

Luis C. Sánchez de Posado of Oviedo University was kind to point out that Asturiella blessi Hoare, 2007 is a junior homonym of Asturiella blessi Becker, 1971. It is proposed to change the name to Asturiella pecki, named for the late Raymond E. Peck of the University of Missouri.

The nearly ubiquitous mite suborder Oribatida, which comprises mostly mycophages and saprophages in organic soil horizons, has a long geological history. Early derivative taxa are known from middle and late Devonian deposits (Norton et al., 1988; Subías and Arillo, 2002) and members of the highly derived cohort Brachypylina have existed since the Jurassic (Krivolutsky and Krasilov, 1977, Selden et al., 2008). The group is commonly represented as inclusion-fossils in amber, with about 100 species known worldwide. Except for four Cretaceous fossils from Siberia (Bulanova-Zachvatkina, 1974; Krivolutsky and Ryabinin, 1976) and Spain (Arillo and Subías, 2000, 2002), the named amber species are of Tertiary age. The majority of these have been discovered in the Priabonian (middle Eocene) Baltic amber deposits of northern Europe (Labandeira et al., 1997; Norton, 2006).

Traditional terms used to describe shell orientation in bivalves are unsatisfactory in three important ways: 1) for poorly known bivalve taxa, unbiased and directionally neutral terms are sometimes needed to replace anterior and posterior where data are incomplete; 2) there is a striking absence of simple terms to apply to the long and short ends of the shell; and 3) the term lateral is either incorrectly or inconsistently applied. in the following discussion, I shall explore each of these issues and suggest remediation.

Yin (1974, p. 25) introduced a new genus, Quadratia for a group of Middle Triassic bivalves in the family Myophoriidae. The type species designated by him is Quadratia quadrata Yin, 1974 [p. 25, pl. 1, figs. 3 (syntype, holotype in original text, right valve), 4a–c (syntype, holotype in original text, left valve), 5 (syntype, paratype in original text); text-fig. 3], the type stratum and locality of which are the Qingyan Formation at Qingyan of Guiyang, Guizhou Province, Southwest China (see also Fang et al., 2009, p. 56, Figs. 16.18–16.21). But this genus name has been preoccupied by Quadratia Muir-Wood and Cooper, 1960 (p. 161, pl. 39, figs. 1–13), which is a member of the Productellidae in the Brachiopoda, with Quadratia hirsutiformis (Walcott, 1884, p. 133, pl. 2, figs. 10, 10a) as the type species, which comes from the White Pine shale of Mississippian age at Applegate Canyon of White Pine County, Nevada, USA. As required by ICZN (International Code of Zoological Nomenclature, Fourth edition; Ride et al., 1999) Article 60.3, I replace Quadratia Yin, 1974, with Guizhoumyophoria, new name, based on the same type species, Quadratia quadrata Yin. The new name is derived from Guizhou Province where the genus occurred.

Rangia des Moulins, 1832 is a small genus of mactrid bivalves that is currently distributed in estuarine waters of the eastern United States, Gulf of Mexico, and Gulf of California (Keen, 1971; Abbott, 1974). (One congener, R. cuneata [Sowerby, 1831], was recently introduced to the Antwerp (Belgium) harbor [Verween et al., 2006].) Although these clams are euryhaline and capable of living in freshwater as adults, they require an estuarine-like salinity regime for successful reproduction and recruitment (Cain, 1973; Hopkins et al., 1974), which has constrained their ability to penetrate the North American continental interior through coastal drainages (Cain, 1974; Swingle and Brand, 1974). the Neogene and Quaternary fossil record of the genus is also restricted to coastal or near-coastal marine-influenced depositional systems, with the exception of Holocene specimens of R. cuneata from two archeological sites in the central United States which were obviously introduced by humans (Baker, 1941; Hill, 1983), and a Pleistocene(?) occurrence of this species from along the Pecos River in New Mexico (more than 800 km from the sea) which has been attributed to transport of Gulf Coast immigrants on waterfowl (Metcalf, 1980; Taylor, 1985). Here we provide fossil evidence that the biogeographic history of this predominantly brackish-coastal genus also includes avian-assisted colonization of a far inland lake in the western United States—Pleistocene Lake Russell, Mono Basin, California (Fig. 1).