A branched, scratch-ornamented burrow system is described from early Pleistocene sediments of Sicily, Italy. The trace fossil occurs in a bed of volcanic ash beneath a shallow marine silty unit and is remarkable in possessing enlarged, ovoid chambers above the multiple branching points of a maze. The structure, named Spongeliomorpha sicula, was probably produced by crustaceans. A likely interpretion is as an agrichnion, in which microbial gardening took place in the chambers.

A new species of the Lower Jurassic genus Dorsettia Whalley, 1985 is described from the Lower Jurassic Badaowan Formation of the Junggar Basin, northwestern China, as Dorsettia sinica new species. It provides additional morphological characters for this genus and is the earliest Jurassic dragonfly in China after the end-Triassic extinction. The occurrence of Dorsettia in England and northwestern China indicates that the end-Triassic extinction probably did not have a drastic influence on damsel-dragonflies, or that the dispersal of damsel-dragonflies was relatively quick during the earliest Jurassic.

The genus Prolagus is very common in the Neogene and Quaternary of Europe, western Asia and northern Africa. However, the complexity of its systematics, mainly based on p3 characters that show great inter- and intraspecific variability, led to an under-utilization of Prolagus in biochronology and palaeogeography studies. A re-analysis of the species of Prolagus recorded in the Escobosa de Calatañazor karst fissure fillings (Duero Basin, northern Spain, MN7/8, late Middle Miocene) includes the introduction of new maxillary and mandibular morphological characters (position, shape and size of premolar and mandibular foramina) and new dental measurements (hypoflexus depth, distal hypercone length, and partial width of upper premolars; relative length of trigonid of lower molariform teeth) to be used for species discrimination within the genus Prolagus. The new morphological characters and measurements introduced in this paper allow for a more accurate taxonomic assignment of Prolagus species, thus improving the estimation of faunal palaeodiversity, detection of sympatric species and taphonomic mixing, and contributing to more reliable biochronological, palaeogeographical, and phylogenetic inferences based on Prolagus.

Articulated meraspid and holaspid exoskeletons of Guangxiaspis guangxiensis from the Guole Township, Jingxi County, Guangxi Province, China, are preserved in mudstone deposited during an obrution event. The species has a short dorsal pre-cranidial median suture that splits ventrally into a pair of posteriorly divergent connective sutures. The rostral plate of G. guangxiensis is thus triangular in outline, as in the co-occurrent Shergoldia laevigata, which also bore a conterminant hypostome. These two taxa appear to be closely related. The cephalic venter of Shergoldia laevigata has recently been interpreted to suggest a diphyletic origin of the median suture within the order Asaphida, but Guangxiaspis guangxiensis, Shergoldia laevigata and other tsinaniid trilobites display several characters reminiscent of members of the non-asaphide suborder Leiostegiina. These include swellings adjacent to the margins of the L1 glabellar lobe, the shape and furrows of the glabella, a semi-circular pygidium with a long and thin axis, and macrospinous first opisthopleurae of the holaspid pygidium. Based on these characters and on other new information on the early ontogeny of other tsinaniids, all these taxa likely belong within Leiostegiina. This suggests that the median suture arose independently in corynexochide and asaphide trilobites. The degree of convergence between S. laevigata and members of the derived asaphide family Asaphidae was remarkable. Guangxiaspis guangxiensis shows marked morphological change during both meraspid and holaspid ontogeny and might include more than a single morphotype.

A hand-specimen, bedding-plane sample of limestone (wackestone) from the Upper Ordovician Waynesville Formation has numerous brachiopod specimens (at least 60) exposed on its surface (Figure 1). The brachiopods have been identified as members of the atrypid species Zygospira modesta (Say in Hall) 1847 (the type species of the genus Zygospira Hall, 1862) and are concentrated in an area measuring approximately 9 cm x 2 cm. A wide range of specimen sizes from juvenile to adult are present and are believed to represent a brachiopod life-assemblage (Figure 2).

A diverse Upper Triassic tropical marine fauna from northwestern Sonora, Mexico, includes 31 taxa of tropical invertebrates including scleractinian corals, spongiomorphs, disjectoporoids, “hydrozoans,” thalamid and nonthalamid sponges, spiriferid and terebratulid brachiopods, gastropods, bivalves, coleoids, and anomuran microcoprolites. They occur within the late Karnian to Norian part of the Antimonio Formation (Antimonio terrane), which is juxtaposed against a fragmented portion of the North American craton. Most of the fauna is also known from the Tethys region. Sixteen Sonoran taxa co-occur in the western Tethys and five have never been known outside this region. Four additional taxa (one identified only at genus level) are geographically widespread. Some taxa occur in displaced terranes of North America, especially in west-central Nevada (Luning Formation). A weak link exists with the California Eastern Klamath terrane but stronger ties exist with Peru. Among Sonoran sponges, Nevadathalamia polystoma was previously recognized only from the Luning Formation, western Nevada. Sponges Cinnabaria expansa, Nevadathalamia cylindrica, and a coral, Astraeomorpha sonorensis n. sp., are also known from Nevada. The corals Distichomeandra austriaca, Chondrocoenia waltheri, Pamiroseris rectilamellosa, and Alpinophyllia flexuosa co-occur in central Europe. Two new taxa, a spongiomorph hydrozoan, Stromatoporidium lamellatum n. sp., and a disjectoporoid, Pamiropora sonorensis n. sp., have distinct affinities with the Tethys. The geographically widespread North American brachiopod, Spondylospira lewesensis, and Pseudorhaetina antimoniensis n. gen. and sp. are among the Sonoran fauna. The Sonoran coleoid (aulacocerid) Dictyoconites (Dictyoconites) cf. D. reticulatum occurs in the Tethys realm and Calliconites cf. C. drakei is comparable with a species from the Eastern Klamath terrane. Calliconites milleri n. sp. is the first occurrence of the genus outside Sicily. The bivalves Myophorigonia jaworskii, M. salasi, and Palaeocardita peruviana are known from Sonora and Peru. Eight gastropod taxa include Guidonia cf. G. intermedia and G. cf. G. parvula, both previously known from Peru, and Eucycloscala subbisertus from the western Tethys. The gastropods are unlike those already known from other North American terranes.

The name Chubutolithes was proposed by Ihering (1922) for an unknown type of fossil occurring in Eocene continental rocks of Patagonia, Argentina. Bown and Ratcliffe (1988) demonstrated that Chubutolithes is a trace fossil; specifically, it is the fossil nest of a mud-dauber. The latter authors also suggested that Chubutolithes was constructed by an insect belonging to the hymenopteran family Sphecidae, and coined the specific name C. gaimanensis for the unusual trace fossil. Comparison with a Recent nest of the mud-dauber Auplopus (Pompilidae; Figure 1.1) suggests that Auplopus is a much more likely candidate as the architect of Chubutolithes than are any sphecid mud-daubers.

Medusaegraptus mirabilis Ruedemann was originally described as a dendroid graptolite and is currently listed in the Treatise on Invertebrate Paleontology among graptolites incertae sedis. Recently, several localities yielding abundant M. mirabilis were discovered, prompting renewed interest in the taxonomic affinities of this species. Based on a study of the morphology and paleoecology of M. mirabilis, this species is herein considered to represent a noncalcified dasyclad alga. Other species of Medusaegraptus are similarly considered.

Medusaegraptid-bearing strata commonly contain other exceptionally preserved fossils and represent conservation lagerstaetten. Consideration of medusaegraptids as dasyclad algae restricts the depth at which these deposits could have occurred.

Bomburia and Ellipsodon are poorly known taxa from the early Paleocene of western North America. New fossil material from New Mexico expands morphological information and allows taxonomic revision of these taxa. Bomburia is a valid genus, whereas Platymastus palantir, previously considered to be a loxolophine arctocyonid, is probably a junior synonym of B. prisca and as such reveals the upper molar morphology of this taxon.

Ellipsodon is highly derived relative to other mioclaenid condylarths. It has a reduced mesial dentition, with the probable loss of the P1/p1. P2–3/p2–3 are reduced and show a simple incisor-like morphology. M1/m1 and especially M2/m2 are simple with highly inflated protocones/protoconid-metaconids accentuating a mortar-and-pestle-like chewing function. The M3/m3 are more reduced than in any other mioclaenid.

Mioclaenidae is monophyletic and endemic to western North America. There is no support for a close relationship between Mioclaenidae and South American or African ungulates.

In the course of ongoing revision of the ant genus Myrmica Latreille, 1804, we located, in the collections of the Russian and Polish Academies of Sciences, pieces of Baltic Amber (Late Eocene, ca. 40 Ma; earlier this amber was considered to be Oligocene, e.g., see Wheeler, 1915; Larsson, 1978; Bolton, 1995; Dlussky, 1997), that each contained a fossilized specimen of Myrmica. We were also fortunate to be given access to a piece of Saxonian Amber (the same age as Baltic Amber) from the collection of Manfred Kutscher that contained three specimens of Myrmica. Four of the specimens belong to two new species. We describe these below, placing them in context with extant species, and we re-appraise all previously described fossil Myrmica, providing a key to the identification of the five extinct “true” Myrmica species.

Ten species of macruran, anomuran, and brachyuran decapod crustaceans, arrayed in eight families, were collected from seven localities in the Jagüel and Roca Formations, west-central Argentina. All of the decapods were collected from the Maastrichtian Jaqüel Formation and a part of the Roca Formation dated as Maastrichtian–Danian. All but one of the taxa, Xanthilites gerthi Glaessner, represent first occurrences in the unit and six had not been described previously from Argentina. Six taxa, Thaumastoplax rocaensis n. sp., Proterocarcinus lophos n. gen. and sp., Lobonotus lobulata n. sp., Glyphithyreus wichmanni n. sp., and Costacopluma australis n. sp. are new. Comparison of the fauna with Cretaceous and Paleogene faunas in Chile, Antarctica, and New Zealand indicates that the Argentinian fauna was strongly influenced by dispersal from lower latitude, Atlantic and Tethyan sources in marked contrast to the high latitude, Pacific affinities of the other faunas. There is no evidence that the Argentinian brachyuran fauna was seriously affected by the K–T extinction event. Seven of the genera from the Roca Formation are known from Cretaceous and Paleogene rocks.

The discovery of platy limestone deposits in northeastern Mexico has led to the collection of well-preserved stramentids of early Turonian age from Vallecillo, state of Nuevo León, and of early Coniacian age from El Carranza, state of Coahuila. Stramentum (Stramentum) pulchellum (Sowerby, 1843) colonized the ammonite shells during the lifetime of the animals, occasionally in two subsequent generations. Colonization of the ammonite shell by Stramentum (S.) pulchellum was hindered by strong ornamentation only. The ammonites did not interfere with their epizoans. Colonization during lifetime shows that these ammonites dwelled in well-oxygenated water levels near the surface, and most stramentids were embedded alive. The known paleobiogeographic occurrence of Stramentum (S.) pulchellum and its long stratigraphic occurrence are considerably enlarged by our findings. The pseudoplanktonic mode of life of Stramentum, and attachment to ammonite shells, may have been a response of a once benthic organism to repeated oxygen-deficient conditions on the seafloor of mid-Cretaceous oceans, i.e., to oceanic anoxic events (OAEs).

The Middle Permian tetrapod fauna of the South African Beaufort Group is taxonomically diverse and includes representatives of all major therapsid groups, including the earliest records of Eutheriodontia. In the Middle Permian, eutheriodonts are represented mainly by large therocephalians, which made up a large proportion of the vertebrate predators in these faunas. Here we describe the skull and partial skeleton of a large therocephalian from the uppermost Tapinocephalus Assemblage Zone (AZ) of South Africa. A combination of features, including the short snout, presence of three to four upper postcanines and presence of teeth on the pterygoid processes, indicates that the new specimen belongs to the earliest-diverging therocephalian family, Lycosuchidae. The presence of a well-developed midline ridge on the ventral surface of the vomer indicates that the new specimen can be referred to Simorhinella baini, a species previously represented only by a tiny juvenile skull. The new specimen forms the basis for a taxonomic re-evaluation of the Lycosuchidae as well as of the geographic and stratigraphic range of the family. We recognize two valid species within the Lycosuchidae: the type species Lycosuchus vanderrieti represented by five specimens and Simorhinella baini represented by two specimens, with an additional 22 specimens currently identifiable as Lycosuchidae incertae sedis. Lycosuchid specimens range throughout the Tapinocephalus and Pristerognathus AZs; specimens of Simorhinella are restricted to the Tapinocephalus AZ, whereas Lycosuchus specimens are documented in both the Tapinocephalus and Pristerognathus AZs.

Conoidal shells of Cornulites celatus n. sp. occur commonly within host coralla of Propora conferta Milne-Edwards and Haime, 1851, sensu lato, from the Laframboise Member of the Ellis Bay Formation (Ashgill: Upper Ordovician) at Pointe Laframboise on western Anticosti Island. Examples have also been found at the same locality in the tabulate corals Paleofavosites sp., Acidolites arctatus Dixon, 1986, and A. compactus Dixon, 1986, and the stromatoporoid Ecclimadictyon sp., but not in other associated tabulate coral species. Growth interference between the shells and their hosts indicates a commensal relationship. C.celatus apparently had a more limited paleoenvironmental range than its principal coral host species, which occurs abundantly elsewhere on the island without its endobiotic partner. The diagnosis of Cornulites is emended to include forms having a two-layered shell wall with a distinctive outer layer consistently preserved as prismatic calcite. This new species extends the known stratigraphic range of cornulitids in commensal relationships with corals and stromatoporoids from the Silurian back to the Upper Ordovician.

Here we report the first detailed reconstruction of the eye and visual system of a Paleozoic ostracod, namely the dimorphic primitiopsid (Palaeocopa) Primitiopsis planifrons Jones, 1887. Evidence from the cuticular lens morphology and its position on the valve suggests that P. planifrons had a naupliar eye, which is the most common optical system in crustaceans. the characters of the eye, such as the separated cuticular lens on each valve and the strongly calcified nature of the lens and its diameter, are concordant with that of some Recent podocopid ostracods in which a divided type of naupliar eye is present. Ray tracing of the reconstructed cuticular lens of the primitiopsid species demonstrates strong spherical aberration and a very long focal length (as in the eye of podocopids), which implies the presence of a spherical mirror (tapetum) below the lens. Study of the ontogenetic change of the valve thickness aids the suggestion that P. planifrons was nektobenthic. the size of its cuticular lens in relation to that of living podocopid ostracods, and the water depth at which these Recent forms occur, indicates that P. planifrons may have lived in a relatively shallow, well lit environment such as the deep subtidal zone. These interpretations are consistent with supposed paleoenvironmental conditions derived from geological evidence. Thus, analysis of the nature and relative size of the eye gives an independent test to help identify paleoenvironmental parameters of long extinct ostracods.

Distinctive galls have been found on a fossil oak leaf from the Miocene Gillam Springs Flora of Washoe County, Nevada. The described galls are located on the leaf surface of Quercus hannibali Dorf, an analogue of the modern species Q. chrysolepis Liebmann. Similar galls are found on extant Quercus, but the fossils seem distinctive enough to warrant description as Antronoides schorni new genus and species. The occurrence of Antronoides schorni coincides with a rapid episode of change from a mesic to a more xeric habitat, with a concomitant shift from an oak-dominated to a conifer-dominated paleoflora. Recent work suggests that speciation and radiation of galling insects is highest in xeric environments, possibly due to decreases in rates of parasitism and disease. This pattern has been documented for modern galling insects and fits the qualitative fossil evidence we present. These galls also support the hypothesis that cynipids in the Antron group originated in Nevada or eastern California and migrated from their point of origin to their current range in the Sierra Nevada and Coast Ranges.

No trilobite species, and very few genera, pass from the Lower (Ibexian) into the Middle Ordovician (Whiterockian), which is a turning point in Laurentian trilobite history. Trilobites from three sections exposing the base of the Whiterock Series (basal Middle Ordovician) in Nevada are described and illustrated. They are attributable to different, and generally more open-shelf, biofacies from the Bathyurid biofacies trilobites described from the Ibex area, Utah, by Fortey and Droser (1996), but include species in common, which allow correlation into the Ibexian type section. At Little Rawhide Mountain the basal Middle Ordovician is developed in Olenid biofacies, described for the first time in western North America from rocks of this age. Correlation based on species-level similarity shows that the “spike” that has been used to define the type base of the Whiterockian (and hence the Middle Ordovician) at Whiterock Canyon is at a level younger than the base of the Whiterockian assumed in recent discussions of its international correlation. The type Whiterock base correlates with the Psephosthenaspis glabrior trilobite Subzone at Ibex, well above the major change in trilobite faunas at the base of the Psephosthenaspis Zone (P. microspinosa Subzone). In all study sections there is an abrupt change of facies after trilobite Zone J, possibly associated with regression. Four new species are described: Cloacaspis tesselata, Harpillaenus rossi, Acidiphorus? lineotuberculatus, and Benthamaspis serus.

The new genus Herminespina comprises extinct South American species of “Thais”-like ocenebrine gastropods with prominent colabral folds and a labral spine. Geographic range extensions into Peru are reported for the late Pliocene H. mirabilis and the late Miocene to Pliocene H. philippii, both previously known only from Chile. A new early Pliocene species, H. saskiae, is described from the Sacaco Basin of southern Peru and compared with an early Miocene muricid from Peru and Chile, Acanthina katzi. Herminespina is one of several genera of Neogene muricids in western South America that bear labral spines.

Specimens of a new species of the Permian waagenophyllid coral genus Waagenophyllum, W. klamathensis, have been recovered from limestone lenses near the top of the Upper Permian Dekkas Formation in the eastern Klamath Mountains, and similar specimens have been collected from an isolated limestone mass in the eastern Hayfork terrane of the southwestern Klamath Mountains, northern California. Another specimen of Waagenophyllum, which may represent another species, has been recovered from another limestone mass in the Hayfork terrane. These specimens of Waagenophyllum, a genus which otherwise is restricted to the Tethyan Province, provide the only tie between the Permian limestone masses of the eastern Hayfork terrane, which also contain typical Tethyan foraminifers, and the eastern Klamath Mountains terrane (McCloud belt), which contains many fossils with non-Tethyan affinities.

We report here the first crustacean microcoprolites from the Sambosan Accretionary Complex (AC) in Japan. Three species of crustacean (order Decapoda) microcoprolites - Payandea japanica n. sp., Favreina tosaensis n. sp., and a species belonging to the genus Parafavreina? sp. are described from the Late Carnian to Rhaetian shallow-water limestones of the Sambosan AC, which were originated on extinct and subsiding volcanoes forming a mid-oceanic atoll-type buildup in the Panthalassan Ocean. Coprolites, which occur within a lagoonal to back-reef facies, provide new insight into the micropaleontology and sedimentology of the Sambosan limestones. Their presence in this tropical shallow-water depositional setting heightens their status of sedimentary facies indicators of such environments. Furthermore the occurrence of these Tethyan coprolites genera in Japan improves our knowledge of the distribution of Triassic crustacean decapods across the Panthalassan Ocean.