W. D. Ian Rolfe

Early land animals in north america: evidence from devonian age arthropods from gilboa, new york.

A new fossil site near Gilboa, New York, is one of only three where fossils of terrestrial arthropods of Devonian age have been found. The new Gilboan fauna is younger than the other two but richer in taxa. Fragmentary remains and nearly whole specimens assigned to Eurypterida, Arachnida (Trigonotarbida, Araneae, Amblypygi, and Acari), Chilopoda [Craterostigmatomorpha(?) and Scuterigeromorpha(?)], and tentatively to Insecta (Archaeognatha) have been found. The centipedes and possible insects may represent the earliest records known for these groups.

Nahecaris stuertzi, a phyllocarid crustacean from the Lower Devonian Hunsrück Slate

Restudy ofNahecaris based on new stereo radiographs and re-examination of actual specimens has added the following new information.Nahecaris ranges in shape from long and slender to short and stout, the carapace from deep and rounded to long and narrow. Carapace ornament consists either of thin ridges parallel to the ventral border or inclined rows of irregular lines or cusps, but these characters cannot be consistently correlated with other variables to permit definition of separate species. The carapace is fused to the head, and possibly to the anterior end to the thorax in the area in front of the median dorsal plate. A post-mandibular pyritised band may represent the carapace adductor muscle, which inserts on the mesolateral carinae. The mandible resembles that ofCeratiocaris, while the maxillae are like those of extant leptostracans. The 8 thoracopods are biramous: they have an exopod with finger-like lobes and a stenopodous endopod. Posteriorly the endopods reduce markedly, forming a conical, anteriorly open feeding basket. The predominance of dorso-ventrally flattened specimens, and the wide ventral gape of the carapace valves suggests those valves were spread apart in life.Nahecaris may have pressed itself to the substrate by flexing the carapace rim outward and incurving the ventral region of the carapace. The stout second antennae may have stabilised and propelled the animal over the substrate.Nahecaris is thought to have been benthic and to have fed, likeCeratiocaris, by lifting the substrate into suspension, as well as by picking up large fragments directly with the mandibles.KurzfassungNeuuntersuchungen alles verfügbaren Materials vonNahecaris und eine Auswertung von Stereo-Röntgenaufnahmen ermöglichen folgende ergänzenden Aussagen:Nahecaris variiert im habitus von schlanken, gestreckten zu kurzen, gedrungenen Formen. Der Carapax weist entweder eine feine, parallel zum Ventralrand verlaufende Streifung auf oder aber schräg dazu liegende feine, irreguläre Linien oder Zähnchenreihen. Ihr jeweiliges Auftreten steht jedoch in keinerlei Zusammenhang mit anderen, ebenfalls variablen Merkmalen und kann nicht als Kriterium für eine Artabtrennung genutzt werden.Der Carapax ist mit der Kopfregion verschmolzen und im Bereich vor der medianen Dorsalplatte möglicherweise auch mit dem Vorderteil des Thorax. Ein postmandibular gelegenes Pyrit-Band dürfte den Verlauf des Adduktor-Muskels nachzeichnen, der am seitlichen Kiel ansetzte. Der Bau der Mandibeln entspricht den Verhältnissen beiCeratiocaris, der der Maxillen denen bei rezenten Leptostraken. Die 8 Thorakalbeine sind zweiästig: ein Exopodit mit finger-ähnlichen Fortsätzen und ein stenopoder Endopodit. Die Endopodite nehmen nach hinten sichtbar an Größe ab und bilden so einen konischen, nach vorn geöffneten Fangapparat.Die überwiegend dorsoventrale Einbettungslage des untersuchten Materials und das weite ventrale Auseinanderklaffen der beiden Carapaxhälften deuten darauf hin, daß beide Hälften auch zu Lebzeiten auseinandergeklafft haben dürften.Nahecaris dürfte fähig gewesen sein, sich durch ein Auswärtskrümmen des Carapaxrandes dem Untergrund anzuschmiegen, den Carapaxrand gleichsam als Kufen nutzend. Die massive 2. Antenne dürfte teils als Stütze gedient haben, teils, urn das Tier auf dem Untergrund vorwärts zu bewegen.Nahecaris wird als Bodenbewohner gedeutet, der ähnlichCeratiocaris nahrungshaltiges Substrat mit den Thorakopoden in Suspension aufwirbelte bzw. größere Partikel direkt mit den Mandibeln aufnahm.

Woolly rhinoceros from the Scottish Pleistocene

Synopsis Evidence for the existence in Scotland of the woolly rhinoceros, Coelodonta antiquitatis (Blumenbach), has previously been confined to one metacarpal bone. An additional tibia, humerus and molar tooth are now known and are briefly described. All finds are from different localities in the Kelvin valley of the Bishopbriggs district, Lanarkshire. Collagen from the humerus has yielded a radiocarbon date of 27 550 years B.P. This date implies either that the bone is derived from an earlier deposit or that the Kelvin valley sands and gravels are much older than recently suggested and of Middle/Late Weichselian interstadial age.

Limb structure, affinity and diet of the Carboniferous ‘centipede’ Arthropleura

Synopsis The limb of Arthropleura is shown to be uniramous and not biramous as suggested by Waterlot and accepted by all subsequent authorities except Størmer. The functional significance of some of the limb features is apparent from comparison with living myriapods. The rosette, K- and B-plates are suggested to be sub-coxal sclerites and not limb segments, appendages or organs as previously maintained. New reconstructions of the limb and of the whole animal are presented. Arthropleura is here regarded as a member of a distinct class of Myriapoda, the Arthropleurida, which differs from all other myriapods in the large number of segments in the limb and in the presence of the rosette plate. A juvenile specimen of Arthropleura has lycopod fragments preserved as gut contents, proving that this creature was herbivorous and not carnivorous as suggested by Waterlot. This herbivorous habit is one of several features indicating parallel evolution of the Arthropleurida and the living polydesmid millipedes.

Form and function in Thylacocephala, Conchyliocarida and Concavicarida (?Crustacea): a problem of interpretation

Differences in the preservation of Jurassic thylacocephalans and conchyliocarids have given rise to different interpretations of the form of these fossils, and thus their mode of life. When evidence from these two groups is combined with that derived from Palaeozoic concavicarids, it becomes possible to unify the several interpretations of this one group of organisms, the Thylacocephala. The group ranges from at least the Silurian to the Cretaceous. A review is given of how these differences of interpretation have arisen, and some resolution is attempted. If the thylacocephalan “anterior structure” is reinterpreted by analogy with hyperiid amphipods as a paired compound eye occupying most of the surface of the head, it explains its bilobed nature and the position of the stomach within the structure, but it raises the difficulty of a post-cephalic origin for the carapace. The simpler solution is preferred of regarding this structure as discrete paired eyes with a smooth cornea and subjacent crystal cones. The raptorial appendages are post-oral and post-adductor in insertion. They are therefore tentatively identified as the maxillae and maxilliped, but verification of the mandibles position is needed to test this. The postero-ventral battery of “body somites” is reinterpreted as paired protopods of abdominal limbs. A respiratory current is deduced to have entered a branchiostegal chamber ventrally, and left it posterodorsally. It is speculated that the looped linear pattern of intra-cuticular spheres in Paraostenia are photophores. The large eyes with small interommatidial angles were probably used to discern low contrast prey or carrion against a dim background. By analogy with hyperiid amphipods, it is suggested that at least some thylacocephalans were mesopelagic predators. They may have attained neutral buoyancy from their food substrate of shark and coleoids.

Angustidontus, a Late Devonian pelagic predatory crustacean

Restoration of the morphology of Angustidontus seriatus Cooper, 1936 based on complete specimens from the Famennian of Nevada and Poland, supports its affinity to the coeval alleged decapod Palaeopalaemon and suggests eocarid (possibly also peracarid) affinities. Predatory adaptation of the thoracopods and the relatively short pereion make this crustacean only super- ficially resemble the archaeostomatopod hoplocarids, because the large grasping appendages of Angustidontus represent the first, rather than second, maxillipeds and acted in the opposite direction: downward. Another similar adaptation of the antennae in the Visean Palaemysis suggests a widespread adaptation to predation among early eumalacostracans. The large sample collected from the Woodruff Formation of Nevada permits biometric characterisation of the grasping maxillipeds of Angustidontus, showing that their highly variable morphology should not be used to define species. All previously described species are therefore here synonymised with A. seriatus .D ifferences in gnathobases of mandibles found in articulated specimens in Nevada, and associated with isolated maxillipeds and articulated specimens possibly representing another unnamed species in Poland, suggest that such mandibles may eventually prove to be taxonomically more significant.

Phyllocarid crustaceans from the Upper Devonian Gogo Formation, Western Australia

Phyllocarids (Crustacea: Malacostraca) from the Upper Devonian (Givetian-Frasnian) Gogo Formation of Western Australia are described and two new species are reconstructed. The mineralized exoskeleton is well preserved in concretions, but the appendages, apart from the mandible, are unknown. Montecaris gogoensis sp. nov. (Echinocarididae) is represented by >600 specimens; a possible second species of Montecaris is represented only by ∼14 specimens of antero-dorsal fragments of the valves, which are highly tuberculate. Schugurocaris wami sp. nov. (Ceratiocarididae) is represented by >300 specimens; a possible second species with a very elongate telson is represented by four specimens. An undetermined species of Dithyrocaris (Dithyrocarididae) is represented by >80 specimens.

Rare phyllocarid crustaceans from the Devonian Hunsrück Slate

KurzfassungAußerNahecaris stuertzi sind Phyllocariden selten im Hunsrückschiefer. Die seltenen und meistens unvollständig erhaltenen Exemplare werden hier beschrieben und sieben verschiedenen Taxa zugewiesen:Heroldina rhenana, Ceratiocarina fam. et gen. indet.,Montecaris? Nahecaris? balssi, Nahecaris sp.,Dithyrocaris? sp., und Rhinocarididae gen. et sp. indet. Fast kein Stück bietet diagnostische Merkmale, die eine Bestimmung auch nur auf dem Gattungsniveau zuließen. Manche Stücke könnten von unterschiedlichen Körperregionen desselben Taxons stammen. Die Phyllocariden des Hunsrückschiefers, unter Einschluß vonNahecaris, überliefern Merkmale, die eine Verwandtschaft mit den leptostracen Malacostraca andeuten. Die Zuweisung der Phyllocariden zur Klasse Phyllopoda durch Schram (1986) wird zurückgewiesen.AbstractPhyllocarids other thanNahecaris stuertzi are rare in the Hunsrück Slate. The few specimens, mostly fragmentary, are here described and referred to seven different taxa:Heroldina rhenana, Ceratiocarina fam. et gen. indet.,Montecaris? sp.,Nahecaris? halssi, Nahecaris sp.,Dithyrocaris? sp., and Rhinocarididae gen. et sp. indet. Almost none of them yields diagnostic characters permitting identification at even generic level. Some may be different body regions of the same taxon. The Hunsrück Slate phyllocarids, includingNahecaris, preserve characters which indicate an affinity with the leptostracan Malacostraca. Schram’s (1986) reassignment of the phyllocarids to the Class Phyllopoda is therefore rejected.

Recent evidence for the age of the Hagshaw Hills Silurian Inlier, Lanarkshire

Synopsis A graptolite fauna discovered in the basal beds of the Hagshaw Hills Inlier suggests an Upper Valentian age. Fragments of stromatoporoid and bryozoan colonies found in the hitherto unfossiliferous Parishholm Conglomerate indicate derivation from a source rock of Wenlock age. Since the Parishholm Conglomerate is thus younger than some part of the Wenlock it supports the recent suggestion that this conglomerate is paraconformable. The new evidence implies that the upper ‘fish’ beds of the Midland Valley inliers are post-Wenlock and therefore Ludlow in age as maintained by Westoll, but that a greater time interval separates upper from lower ‘fish’ beds than was formerly allowed. An overlooked publication by Peach in 1902 records a shelly fauna from the base of the Lesmahagow succession which permits closer correlation between the Hagshaw Hills and Lesmahagow inliers.

Urda mccoyi (Carter 1889), an isopod crustacean from the Jurassic of Skye

Introduction Although they are abundant and widespread in modern marine and terrestrial habitats, isopods are found only rarely as fossils. The fragile nature of their integument, their environmental preference, and their small size reduces preservation potential. Thus, the discovery of a fossil isopod that extends the geological or geographic range warrants notice. This communication reports the first fossil isopod from Scotland and discusses its implications for the generic placement of a previously described species. A single, nearly complete and well-preserved fossil isopod was collected from the Oxfordian of Staffin Bay, northern Skye. Comparison of this specimen with type specimens, where possible, and illustrations of previously described fossil isopods suggests that it is morphologically similar to the type specimens of Palaega mccoyi Carter, 1889, from the Upper Greensand (Albian: Cretaceous) of Cambridge, England and should be assigned to that species. Further, evaluation of the morphology of Palaega mccoyi, in the context of this study, requires that the species be reassigned to Urda Münster. Systematic description Order ISOPODA Latreille 1817 Suborder UNCERTAIN Family Urdidae Kunth 1870 Urda mccoyi (Carter, 1889) Fig. 2. Material. Unique three-dimensional specimen in calcareous concretion, GSE 15083, in collections of British Geological Survey, Edinburgh. Collected by James McCall of H.M. Geological Survey in June 1936, from ‘just below top red rib praecordatum’ Subzone, of what is now termed the Dunans Clay Member of the Staffin Shale Formation (Sykes 1975), at Point 5 (Anderson and Dunham 1966, fig. 10; Wright 1973) in Staffin Bay, northern Skye (Fig. 1). . . .