Exuviae comprising immature growth stages allow the tracing of morphological and morphogenetical features of the reduced-eyed phacopid species Plagiolaria poothaii Kobayashi and Hamada, 1968, from the Early Devonian of Satun Province, southern Thailand. Biometric and morphometric approaches have been used to characterize the shape changes. This is the fourth phacopid genus for which ontogenetic information is known. Ontogenetic features of this species are generally similar to those of Phacops and Weyerites. However, the ankylosis of the facial sutures occurs at the end of the meraspid period, later than in Phacops, and this is probably a derived character.

Holmiids are a major component of the trilobite fauna in the middle part of the Montezuman Stage, the lowermost stage of the Cambrian of Laurentia with a continuous trilobite record. They are less common in the upper Montezuman where nevadiids predominate and other trilobite families appear. New material from western Nevada allows a revision of these holmiids. Palmettaspis parallela Fritz, 1995 and Palmettaspis cometes (Fritz, 1995) are assigned to a new genus, Montezumaspis, based primarily on thoracic characters, including a prominent axial spine on the thorax. A second new genus, Grandinasus, is based on Esmeraldina argenta (Walcott, 1910), in which the L3 lobe is incorporated in an expanded anterior lobe (LA) of the glabella. New species described are Esmeraldina elliptica, Grandinasus auricampus, G. patulus, Holmiella falx, and H. millerensis. The Laurentian taxa appear to be more primitive than the holmiids of Baltica by having simple, unfurrowed ocular lobes that are separated from the LA by an axial furrow. Three informal biofacies are suggested with a holmiid-dominated biofacies in a deep subtidal dysoxic environment, and two nevadiid-dominated biofacies in shallower subtidal environments.

Upper Eocene and lower Oligocene deposits of the Jebel Qatrani Formation, Fayum Depression, Egypt, have provided a number of skulls and other bones that belong to a species of snakehead (Channidae). This material is morphologically more similar to species of Parachanna, rather than species of Channa, and is here described as a new species, Parachanna fayumensis. It differs from the other species of the genus in possessing a prominent tooth patch on the posterior end of the parasphenoid.

This new species of channid is the oldest member of the family known from Africa. Prior to this record, the oldest African fossil channid material was found in Mio—Pliocene deposits. This lack of information on the African fossil record leads to biogeographic reconstructions in which channids were believed to have arisen in Asia and invaded Africa through fresh waters, only after the two continents were connected in the Miocene. the Egyptian material shows that channids were in the fresh waters of Africa in the latest Eocene. Either a freshwater connection existed between Africa and Asia before or during the late Eocene, or members of the Channidae were able to migrate through marine waters to attain their current distribution.

Calcareous horizons in the Qasr and Hammamiyat members (Lower Devonian, ?Pragian and lower Emsian) of the Jawf Formation, northwestern Saudi Arabia, yielded a rich assemblage of microremains from acanthodian, placoderm, chondrichthyan, and sarcopterygian vertebrates. The most abundant elements are scales from acanthodians Nostolepis spp., Milesacanthus ancestralis n. sp., Canadalepis? sp., and Gomphonchus? fromensis, scales and dermal bone fragments from acanthothoracid and ?rhenanid placoderms, and teeth from onychodontids. Rarer occurrences include ?chondrichthyan scales of several different morphotypes, and petalichthid and ?ptyctodontid placoderm elements. The Qasr Member assemblage shows a close resemblance to slightly older faunas from the Lochkovian of Brittany and Spain. The Hammamiyat Member microvertebrate fauna shows closest affinity with that of the stratigraphically lower Qasr Member, with similarities also to coeval faunas from southeastern Australia, late Emsian/Eifelian faunas from west-central Europe, and the Givetian Aztec Siltstone fauna from Antarctica.

We describe a new tritheledontid, Elliotherium kersteni n. gen. and sp., on the basis of a partial skull collected from the lower Elliot Formation (Upper Triassic; Euskelosaurus Range Zone) on the farm Beatrix, Free State Province, South Africa. Although similar to Pachygenelus, the genus differs from other South African tritheledontids in its higher maxillary postcanine tooth count, lack of labial cingula on the upper postcanine teeth, shorter secondary palate, retention of a median vomerine ridge behind the secondary palate, and smaller interpterygoid vacuity. With regard to these features, Elliotherium is most similar to the South American tritheledontid Chaliminia. Elliotherium is autapomorphic in its possession of a long parasphenoid rostrum, ventrally depressed secondary palate, medially convex margins of the interpterygoid vacuity, and a thin lamina of palatine covering the interpterygoid vacuity. Although Elliotherium is the stratigraphically lowest positioned tritheledontid from southern Africa, it is still probably later occurring than the South American taxa Chaliminia or Riograndia. Based on a revision of a previous analysis of advanced cynodont relationships, we propose a sister-group relationship between Elliotherium and Chaliminia, although support for this pairing is weak.

Two new species of scutelluine styginid trilobites are described from Frasnian strata in the Virgin Hills Formation in the Canning Basin of Western Australia. They are placed in the genus Telopeltis n. gen., reflecting the fact that their final occurrence in the late Frasnian, up to the latest Frasnian Kellwasser extinction event, is the last known record of scutelluine trilobites. As such, it also represents the youngest record of the order Corynexochida. The two species, Telopeltis woodwardi n. sp. and Telopeltis microphthalmus n. sp., are unlike most other scutelluines in possessing extremely vaulted pygidia and showing trends to eye reduction. Such eye reduction is a common feature of late Frasnian trilobites. The characteristic morphological features of this small genus are indicative of evolution of this last scutelluine by paedomorphosis.

The fossils described here were collected from the Lower Triassic (Olenekian) at two Majiashan sections in Chaohu City, Anhui Province, East China. Nine species belonging to five genera are introduced, including a new genus, Chaohuichthys, and some undetermined or unnamed fish specimens are discussed. The fish assemblage from Majiashan covers most of the Lower Triassic marine bony fish taxa known from China.

The skeletal anatomy of the Early Permian eureptile Thuringothyris mahlendorffae from the Bromacker Quarry, Germany, is redescribed on the basis of several new specimens. The taxon retains some plesiomorphic characters, such as an ectopterygoid and a tabular, but it also possesses low neural spines and nonswollen neural arches, a combination that is unique for early eureptiles. A phylogenetic analysis places Thuringothyris as the sister taxon of Captorhinidae, excluding any potential “protorothyridid” affinities. Implications of this study are that the swollen neural arches of captorhinids and araeosceloids might have evolved independently, that a downturned rostrum occurred only later in captorhinid evolution, and that the European Permian is important to the understanding of the origin of eureptiles.

Eosuchus minor (Marsh, 1870) is based on skeletal fragments from the Late Paleocene or Early Eocene of New Jersey, but more complete material from the Late Paleocene of New Jersey, Maryland, and Virginia permits a detailed description and systematic assessment. It is a slender-snouted form and can be distinguished from most other crocodylians on the basis of an enlarged quadrate foramen aereum; a distinct W-shaped rugosity along the ventral margin of the basioccipital tuber; a prominent crest on the lateral braincase wall encompassing portions of the quadrate, pterygoid, and basisphenoid, forming the lateral wall of the lateral eustachian canal at its ventralmost extent; and arrangement of dentary alveoli into couplets. Specimens of larger crocodylians from the same units may represent either the adult form of E. minor or a separate taxon. The enlarged quadrate foramen aereum, couplet arrangement of dentary alveoli, and basioccipital tuber shape are shared with Eosuchus lerichei from the Late Paleocene of Europe. Eosuchus lies within Gavialoidea crownward of the basal forms Thoracosaurus and Eothoracosaurus. The braincase of Eosuchus is intermediate between that of Thoracosaurus and that of Gavialis; the basisphenoid retains a short (but externally visible) descending lamina, but the basisphenoid is also anteroposteriorly expanded at the level of the median eustachian foramen.

The appendicular skeleton of the Lower Permian temnospondyl Eryops megacephalus Cope, 1877, described and figured in detail, is similar to that of most temnospondyls, except that it is highly ossified. It displays terrestrial adaptations, including a reduced dermal pectoral girdle and comparatively large limbs, characterized by well-developed processes for muscle attachment. While many features that were previously unknown or uncommon among temnospondyls were identified, no apomorphies of the appendicular skeleton particular to Eryops were found. Some characteristics of the endochondral postcranial skeleton found in well-ossified temnospondyls, such as Eryops, are absent in less well ossified temnospondyls due to immaturity or paedomorphism. The effects of heterochronic processes on the morphology of the postcranial skeleton of temnospondyls and the implications for cladistics are discussed; the appendicular skeleton of Eryops is considered hypermorphic. Within the Temnospondyli, the Eryops appendicular skeleton is most similar to that of the Dissorophoidea, and most dissimilar to both the most plesiomorphic temnospondyls and the secondarily aquatic Mesozoic stereospondyls. The appendicular skeletons of well-ossified Late Permian and Mesozoic temnospondyls are not as robust as that of Eryops.

Surprisingly, Eryops, in common with other well-ossified temnospondyls, shares many derived features of the appendicular skeleton with seymouriamorphs and diadectomorphs. The presence of these previously unrecognized synapomorphies (relative to stem tetrapods and embolomeres) provides evidence for an alternative hypothesis of relationships of early tetrapods, suggesting that the Temnospondyli and seymouriamorphs plus diadectomorphs are sister taxa.

Morphological and biometrical variability is analyzed in Hipparion primigenium (V. Meyer) from four Vallesian and Turolian locations in Spain (Masía de Barbo, Puente Minero, Nombrevilla, and Los Valles de Fuentidueña). Previously unstudied remains of Hipparion from La Roma 2 (Teruel Province, Spain) are described and tested by multivariate analysis. This form is compared with: 1) Hipparion primigenium (or Hippotherium primigenium) from the above-mentioned Spanish localities; 2) large-sized specimens from Çalta (Turkey) and Pavlodar (Kazakhstan); 3) forms from the locality type of Eppelsheim, Höwenegg, and Dürkheim (Germany), and Nikiti 1 (Greek); and 4) specimens from two other Spanish localities, Concud and Venta del Moro. Hipparion remains from La Roma 2 are identified as Hipparion laromae n. sp. by body mass and morphological characteristics, and confirmed by bivariate and multivariate analyses. The faunal assemblages indicate a late Vallesian age (MN10) for La Roma 2 locality and an early Turolian age (MN11) for the Puente Minero locality.

Histology of newly discovered ganoid scales from the lower Bahariya Formation, in the Bahariya Oasis of western Egypt, confirms the presence of polypterid osteichthyans in this early Cenomanian locality. These fossils, occurring in the ~97 million-year-old lower Bahariya sequences, are among the earliest known polypterids. the Bahariya scales exhibit four tissues: ganoin, dentine, isopedine (elasmodin), and a basal plate of cellular bone, confirming their inclusion within the Polypteriformes. They have a discontinuous ganoin layer, present only as highly variable ridges and bosses. Dentine along the edges of the ganoin ridges appears to have undergone active remodeling, suggesting that the ganoin ridges represent the remnants of a continuous ganoin cover. Modern polypterids inhabit exclusively freshwater environments. Polypterids are not rare in the lower Bahariya Formation. Their presence in these coastal sediments suggests that freshwater habitats lay close to the site of deposition of this sequence during the early Cenomanian.

The skull of a carnivorous therapsid from the Tapinocephalus Assemblage Zone of the Beaufort Group, Middle Permian of South Africa, is described as a new burnetiamorph biarmosuchian. Pachydectes elsi n. gen. and sp. is distinguished from all other therapsids by its possession of a conspicuous pachyostotic maxillary boss that sheathes the root of the upper canine. It shares the presence of a preparietal ossification with other biarmosuchians and a pachyostotic boss below the postorbital bar with other burnetiamorphs. Pachydectes is the first burnetiamorph known from along the Ecca-Beaufort contact in the eastern part of the Karoo Basin and only the second burnetiamorph to be described from the Tapinocephalus Assemblage Zone. All other South African burnetiamorphs, save Bullacephalus jacksoni, are known from much younger biozones of the Beaufort Group. Our phylogenetic analysis links Pachydectes and Bullacephalus, which are the stratigraphically lowest-occurring taxa, with Burnetia, the burnetiamorph known from the highest position in the lower Beaufort Group. This result suggests that most of the history of biarmosuchians in South Africa is unrecorded.

A new fossil Ictiobus species is described, based on an abundant collection of well-preserved isolated bones found in lacustrine deposits of Pliocene (Blancan) age near Tula de Allende, state of Hidalgo, central Mexico. This fossil Ictiobus species shows the diagnostic character of the genus. In the palatine bone the ethmoid process is longer than the premaxillary process. Suspensorial pleural ribs with trapezoidal shape and a dentary bone with extremely short and wide gnathic ramus are the characters that support the creation of this new Ictiobus species. The fossil record of Ictiobus, the first known in Mexico, extends the paleogeographical distribution known of this genus, which had been previously restricted to the USA.

A new eutherian mammal of uncertain taxonomic position is described on the basis of well-preserved dental and gnathic specimens collected from localities in the Paleocene Paskapoo Formation of Alberta, Canada. Horolodectes sunae new genus and species is represented by seven incomplete maxillae, eleven incomplete dentaries, and numerous isolated teeth, together preserving nearly all of the postcanine dentition. The unusual dentition of Horolodectes n. gen. consists of trenchant, posteriorly leaning premolars in combination with comparatively primitive molars, suggestive of a masticatory cycle that consisted primarily of shearing and, to a lesser degree, horizontal grinding. Included among the specimens of Horolodectes is an incomplete dentary of an immature individual, with the teeth having been in various stages of eruption at the time of death. Although the dentition of Horolodectes broadly resembles that of apheliscine hyopsodontids, pentacodontine pantolestids, and “ungulatomorphs” among eutherian mammals, significant differences in the coronal structure of the teeth prevent unequivocal referral of Horolodectes to any of these groups, or to any known eutherian order.

The earliest known record of lingulid-coral associations is described from Ashgill tabulate corals preserved on Manitoulin Island, Ontario. Lingulid infestation of tabulate corals and stromatoporoids also is locally abundant in Ashgill and Llandovery limestones on Anticosti Island, Québec, and these preserve the new lingulid species Rowellella? anticostiensis inside the cavities of Trypanites borings. In all examples, lingulids appear to nestle in previously formed Trypanites, likely in a dead host coral or stromatoporoid. In some instances in the Silurian of Anticosti, regeneration of host growth while infested by lingulids is evidenced by a new type of compound trace fossil, Klemmatoica linguliforma new ichnogenus and ichnospecies. Similar endosymbiotic relationships previously observed in Silurian corals from Wales and Sweden suggest that the lingulid association with tabulate corals and stromatoporoids was widespread in early Paleozoic shallow marine settings.

The present note aims to clarify the taxonomic status of the calmoniid trilobite Paranacaste pontagrossensis Popp, 1989, from the Ponta Grossa Formation, Lower Middle Devonian (Eifelian) of the Paraná Basin, Brazil.

Postibullinid edrioasteroids are a small clade of discoidal edrioasteroids that are locally common members of Devonian to Pennsylvanian, shallow marine, hard substrate faunas in North America and Europe. A small discoidal theca, narrow, highly elevated ambulacral cover plates, a highly elevated anal pyramid, and in many forms a posterior oral protuberance characterize this clade (Bell, 1976b; Sumrall et al., 2000). Here we describe the oldest known postibullinid, Pyrgopostibulla belli n. gen. and sp., a species that differs from other postibullinids by having a well-developed pedunculate zone and a complex, five-plate pattern of ambulacral cover plates. A dense population of these edrioasteroids preserved at a single stratigraphic horizon provides a census sample of individuals that were killed as a part of a final and abrupt burial pulse on this Lower Devonian hardground (Cornell et al., 2003). As such, this case study provides insight into the ontogeny and colonization strategies of isorophinid edrioasteroids.

Two new records of gomphotheriid proboscideans, one identified as Rhynchotherium and the other as Cuvieronius, are reported in México. Both records are in the southwesternmost points of their known distributional range.

The remains of both genera consist of molars and tusks. Their measurements were compared with data available from the literature and collection specimens. The molar index of Rhynchotherium shows statistical differences between m2 and M2, and m3 and M3. However, differences between the m3 from both genera are not statistically significant, despite slight morphological differences.

This suggests that metric and morphological information should be included for a reliable identification of isolated molars and, if available, any other data of the associated tusk.

All known records relating to both genera suggest that they found southwestern México favorable for use as a dispersal corridor to South America, likely due to the region's tropical or subtropical climate. However, some distributional gaps in central México need to be resolved for Rhynchotherium. There are also important populations of Cuvieronius in central México, and preliminary information suggests that they occupied at least parts of eastern México, as well.

A new actinopterygian, Cuneognathus gardineri new genus and species, is described from the Devonian (Famennian) Obrutschew Bjerg Formation of East Greenland on the basis of multiple incomplete specimens. Cuneognathus most closely resembles Limnomis from the Famennian Catskill Formation of Pennsylvania, and, like that taxon, is known exclusively from freshwater deposits. A cladistic analysis with an ingroup of 13 actinopterygians and an outgroup of five sarcopterygians explores the relationships between the new genus and some of its better-known Devonian contemporaries, and recovers the same four topologies regardless of the implementation of limited character ordering. Cheirolepis is resolved as the most basal of well-known Devonian actinopterygians, consistent with a majority of previous studies. A novel sister-group relationship between Howqualepis and Tegeolepis is found in all trees. Disagreement between the most parsimonious cladograms is concentrated in a clade whose members are often informally referred to as ‘stegotrachelids.’ Cuneognathus and Limnomis are resolved as sister taxa within this large radiation along with the pairings of Moythomasia dugaringa plus M. nitida and Krasnoyarichthys plus Stegotrachelus. the arrangement of taxa is conserved when the enigmatic Dialipina is added to the analysis, although the reconstructed position of that genus above both Cheirolepis and Osorioichthys seems improbable. Our scheme of relationships suggests that actinopterygians invaded freshwater environments at least four times during the Devonian, while age constraints indicate that many of the cladogenic events between ingroup taxa included in this study occurred during or before the Givetian.