A new genus and species of Asteroidea (Echinodermata), Embolaster graffhami, Embolasteridae, n. fam., is described from the Upper Ordovician Bromide Formation of Oklahoma. Embolaster is important in part because of the presence of two similar ossicles on each interbrachial plane in the axillary position; only a single axillary is recognized in most Paleozoic asteroids. The axillary traditionally has been considered to be a part of the marginal series, although marginals are almost always paired. The two ossicles are interpreted as axillaries and the homologues of an ancestral proximal marginal pair. The odontophore, which lies distal to the mouth angle pair of most asteroids, tentatively is the homologue of the proximal axillary.

Embolaster also is important because of the presence of an ossicular series between the ambulacrals and the putative adambulacrals. An extra ossicular series in this position is known from taxa traditionally assigned to the ophiuroids; however, other characters of Embolaster indicate asteroid affinities for this genus. The two ossicles lateral to and aligned with the ambulacrals in Embolaster are interpreted as homologous with the similarly arranged radial virgal series of somasteroids, although specific ossicular homologies are problematic.

A part of the mouth frame structure of Embolaster is exposed, although it is tiny and therefore difficult to interpret. The mouth frame arrangement is reminiscent of those of somasteroids, with small, narrow circumorals and apparent buccal podial basins directed toward the mouth opening. Many of the striking characters of Embolaster probably are plesiomorphic; apomorphies are difficult to ascertain.

Systematics of the trilobite subfamily Koneprusiinae Vaněk and Pek, 1987 are revised on the basis of new material and a comprehensive parsimony analysis. New taxa include the genus Nevadaprusia (type species N. cortezensis n. sp.) from the Pragian of Nevada and the species Laethoprusia graffhami n. sp. from the Lochkovian of Oklahoma, L. cozarti n. sp. from the Lochkovian of Tennessee, and Laethoprusia n. sp. A from the Sheinwoodian of Arctic Canada and the southern Mackenzie Mountains. Nevadaprusia insolita (Haas) is revised on the basis of new material. Laethoprusia and Nevadaprusia are interpreted as sister taxa, and Koneprusia and Isoprusia are successive sister groups to the Laethoprusia/Nevadaprusia clade.

From the Aseelah Unit (Saal Formation), Batain Coast (eastern Oman), 48 bryozoan species were described. Eight species of them are new: cystoporids Cystodictya angusta n. sp. and Sulcoretepora orientalis n. sp., trepostomid Ulrichotrypella omanica n. sp., rhabdomesids Streblotrypa (Streblotrypa) binodata n. sp., Rhabdomeson coniforme n. sp., R. latum n. sp., Orthopora punctata n. sp., and phyloporine Rhombocladia quasiminor n. sp. A new combination is erected: Streblotrypa (Strebloscopora) katoi Sakagami, 2000 n. comb. Fifteen species are described in open nomenclature. The fauna shows mainly Lower to Middle Permian age, and paleobiogeographic connections to the Urals, southeast Asia and Australia.

The central muscle scar field of the beyrichioidean palaeocopid ostracodes includes an adductor muscle scar composed of many polygonal scars, a long mandibular scar composed of eight individual scars, and an oval frontal muscle scar. Probably, as in the extant ostracodes, the muscle scars served as attachment points for the closing muscles as well as for the muscles and chitinous supporting structures from the appendages. The fulcral depression, on which the dorsal apex of the mandible pivots in recent ostracodes, has also been recognized in the Early Carboniferous beyrichiids and paraparchitids.

The pore systems of the beyrichioideans are more advanced than assumed so far, and they include, documented for the first time, the secretory (‘exocrine’) pores and ‘marginal’ pores in Paleozoic beyrichioideans. It seems likely that the development of these pores, was related to the transition of beyrichioideans from shallow marine into unstable, possibly brackish, water paleoenvironments.

The partially calcified inner lamella and the ‘marginal’ pore canals are apomorphies of some Early Carboniferous beyrichioideans. Internal features of the paraparchitids confirm their beyrichioidean affinity. The adductor and mandibular scars are plesiomorphic in the Beyrichiidae and Paraparchitidae. The presence of mandibular scars and fulcral depressions may indicate that these ostracodes were actively feeding bottom crawlers.

Echinoderm skeletal debris from the Early–Middle Cambrian boundary Micmacca Breccia of Morocco includes the oldest known holomeric columnals. The original calcite of these ossicles is coated and replaced by iron oxides, occasionally overlain by a late coating of silica, and preserves with high fidelity fine details of their three-dimensional microstructure. Irrespective of their external morphology, columnals can be divided into three groups based on the distribution of stereom microfabrics, which we suggest indicates the presence of at least three different holomeric stemmed taxa. One of these columnal types has well-developed galleried stereom perpendicular to its articulation facets, a sure sign that long, penetrative collagen bundles bound columnals together, as in modern stemmed crinoids. This columnal morphology also shows a primitive type of interlocking articulation, which we term parasymplexy and which may have helped to counter torsional stresses. The two other columnals either lacked fibrous connective tissue or had shallow, non-penetrative fibers between columnals.

We describe Numbigilga ernielundeliusi new genus and species, a highly unusual marsupial represented by a partial right mandible with p2–m4 and a left upper molar from early Pliocene deposits at Bluff Downs, Queensland, northeastern Australia. Numbigilga n. gen. is characterized by a bunodont dentition with a number of striking specializations, and we refer it to Numbigilgidae new family. This taxon shares a range of dental apomorphies with various bunodont marsupial groups from the Late Cretaceous of North America and Paleogene of Gondwana. However, many of these features are most likely highly homoplastic within marsupials, reflecting convergent adaptations to a frugivorous-omnivorous diet. Other dental characters suggest possible affinities to the Australian order Peramelemorphia (bandicoots). Alternatively, Numbigilga may be a representative of an entirely new order of Australian marsupials. In the absence of more nearly complete specimens that might clarify its relationships, we refer Numbigilga to Marsupialia incertae sedis. We consider the distributions of a number of dental characters in bunodont marsupials and argue that no North American Late Cretaceous taxa can be convincingly referred to the order Polydolopimorphia. Thus, polydolopimorphians continue to be known only from the Cenozoic of Gondwana, with no fossil evidence that their initial divergences occurred in North America.

Pectinifrons abyssalis new genus and species is an early Ediacaran (ca. 565 Ma) rangeomorph from the Avalon Peninsula of Newfoundland. It is known from more than 200 specimens from the Mistaken Point and Trepassey formations, and is typically preserved as a comb-shaped ridge on the top of mudstone beds beneath volcanic ashfall tuffs. Morphologic and taphonomic features suggest that the living organism consisted of two parallel series of soft rangeomorph fronds, alternately branching in an opposite arrangement from an elongate, tubular pedicle rod. The pedicle rod and the struts that represent the central stalks of the fronds were originally composed of resistant material that did not decompose until after lithification of the overlying ash bed. The fronds themselves were originally composed of a soft, non-resistant material that readily degraded, resulting in their extremely rare preservation as impressions on the bedding surface. Biometric analysis implies that Pectinifrons grew primarily by strut/frond addition, with later inflation of these elements. Pectinifrons is one of the first rangeomorph taxa to display evidence of possible age cohorts comparable to those observed in modern macrobenthic organisms.

Two types of evidence for insect ovipositional activity (i.e., actual egg chorions and ovipositional damage) occur on Nilssoniopteris (bennettitalean foliage) leaf cuticles from the Carnian of Austria and provide a rare direct insight into insect egg morphology and oviposition in the Late Triassic. The egg chorions have exclusively been found on N. haidingeri leaves, where they are attached to the outer surface of the abaxial cuticle; one specimen suggests that the eggs were arranged in circles. It is impossible at present to determine the affinities of the eggs; possible producers may be beetles, dragonflies, sawflies, or other allied basal Hymenoptera. Ovipositional damage occurs on N. angustior leaves in the form of lenticular egg impressions surrounded by a narrow, elevated margin. The impressions are visible on the ad- and abaxial cuticle, and coincide when both cuticles are superimposed, which indicates that the eggs producing these impressions were injected into the interior of the leaf. Producers of eggs that may have caused these damages are perhaps dragonflies or damselflies. The restricted occurrence of the two types of ovipositional activity suggests that some kind of host specificity existed, perhaps related to specific preferences in larval diet.

The taxonomic status of the Lower Cretaceous non-marine ostracode genera Hourcqia Krömmelbein and Pattersoncypris Bate is discussed. From a detailed analysis of the type species of these genera, and several other species attributed to them, it was possible to conclude that both genera are invalid. Hourcqia africana Krömmelbein, the type species of this genus, has an antero-ventral beak, and it is in all other respects identical to Cypridea Bosquet, and therefore should be transferred to this genus. The subspecies originally referred to as Hourcqia africana confluens Krömmellbein and Weber, 1971 is subsumed within Cypridea africana. Secondly, the genus Pattersoncypris, as the result of a study of its type species, P. micropapillosa Bate, is shown to be a junior synonym of Harbinia Tsao. Both, Hourcqia and Pattersoncypris must therefore be suppressed. Cypridea africana (Krömmelbein) occurs in Brazil, Congo, and Gabon in strata deposited during the rift stage, restricted to the late Barremian to early Aptian interval. Harbinia micropapillosa (Bate) occurs in Brazil and Liberia, but it is restricted to the gulf stage, i.e. the late Aptian to early Albian interval. Amended diagnoses for the genus Cypridea and species Cypridea africana and H. micropapillosa are given.

A large number of well-preserved immature exoskeletons enable the first detailed quantitative description of the ontogeny of the trinucleid Marrolithus bureaui (Oehlert, 1895) from the Lower Caradoc of the Armorican Massif (Armorica, northwest France). For the accurate description of cephalic features, a landmark-based approach was adopted in order to recognize ontogenetic instars and to establish the patterns of size increase and shape change during ontogenetic development. The quantitative analysis permitted the demonstration of a progressive shape change in agreement with ontogenetic ordination and a comparison of the timing of size and shape changes. Changes that took place during the meraspid period included, in particular, the development of a more pronounced sub-quadrangular cephalic outline, a compression (sag.) of the glabella and a size decrease until disappearance of the alae in late stages. This quantitative ontogenetic reconstitution of Marrolithus bureaui might be considered as a reference for the better understanding of phylogenetic affinities between other trinucleid species.

A new brachiopod fauna is described from the Early and Middle Permian of Zadoi and Zhidoi counties, southern Qinghai (Changdu block), northwest China. This fauna includes 13 species in nine genera with Spinomarginifera concentrica n. sp. and Transennatia waterhousei n. sp. The Early to Middle Permian brachiopod fauna from southern Qinghai is very similar to the contemporary Cathaysian faunas of South China with which the new fauna shares 70 per cent of its species. On the other hand, the Qinghai brachiopods also demonstrate a significant link with the Permian brachiopod fauna of the Sino-Mongolian-Japanese Province in northeast China, as suggested by Marginifera septentrionalis and Attenuatella. In particular, the occurrence of the bipolar brachiopod genus Attenuatella suggests that southern Qinghai may have played an important role as a biogeographic stepping stone in the marine faunal interchanges between the northern and southern hemispheres during the Early and Middle Permian.

Cretaceous bryozoans from western North America are very poorly known. This paper describes twelve species of cheilostomes from the Upper Cretaceous of southern California and Baja California. The only previously described bryozoan, Ceriocava eastoni Woollacott, 1966, from the Holz Member (?Turonian–Campanian), Ladd Formation of the Santa Ana Mountains, is transferred from Cyclostomata to Cheilostomata, made the type species of the new genus Zimmerella and placed in the family Chiplonarinidae. The following new Campanian– Maastrichtian species are described from the Rosario, Point Loma, and Cabrillo formations of San Diego County, California and Le Misión, Baja California: Wilbertopora sannerae sp. nov., Onychocella schopforum sp. nov., Trichinopolia californica sp. nov., and T. lata sp. nov.

Parablackwelderia is the oldest known stalk-eyed trilobite and thrived during the middle–late Cambrian (Guzhangian Age) in eastern Gondwanaland. The elongated palpebral lobe extends outward and forward from the anterior corner of the cranidium and shows positive allometry, becoming markedly longer and relatively thinner in large specimens. The animal occurred in muddy environments and may have been a predator that burrowed for concealment. Stalked-eyes were independently derived in several trilobite clades, but whenever they appeared were restricted to small numbers of taxa and thus do not appear to have served as a key innovation that promoted extensive diversification of species bearing the structure. The stalk-eyed condition in trilobites has a striking modern analog in the hypercephaly of diopsinid flies, where it is commonly associated with mate recognition and mate selection. We document the first occurrence of Parablackwelderia in Shandong, North China and describe a new species, Parablackwelderia luensis sp. nov.