| 1. |
- Ebbestad, Jan Ove, 1967-, et al.
(author)
-
Ordovician (Caradoc) Gastropoda of the Katkoyeh Formation, Kerman Province, Iran
- 2008
-
In: Geobios. - 0016-6995 .- 1777-5728. ; 41:5, s. 605-624
-
Journal article (peer-reviewed)abstract
- Seven taxa of gastropods are described from the Ordovician (Caradoc) upper Katkoyeh Formation of the Kerman region, east-central Iran.Three are named species and four are under open nomenclature. The most abundant is the minute bellerophontiform Tritonophon peeli Horny´,1977, indicative of a shallow water plectonotid community. Shell material is not preserved in this species, but a small, simple bulbous protoconch ispresent. Two new species are Slehoferia pachyta and Nonorios kleistos, both with prominent thick-shelled conchs. Shell repair is documented inboth of these forms, interpreted as a result of failed predation. Other micromorphic species occur in the samples, but only Tropidodiscus sp. andNonorios? sp. are named. The Kerman assemblage is comparable directly with similar, closely coeval faunas in Bohemia, France, Portugal,Morocco, and Italy, corresponding with the Palaeozoic Mediterranean Province of northern peri-Gondwana.
|
|
| 2. |
- Hoel, Ole
(author)
-
Cementing strophomenide brachiopods from the Silurian of Gotland (Sweden) : Morphology and Life habits
- 2007
-
In: Geobios. - : Elsevier BV. - 0016-6995 .- 1777-5728. ; 40:5, s. 589-608
-
Journal article (peer-reviewed)abstract
- Dorsal valves of the cementing strophomenide brachiopods Leptaenoidea silurica Hedström and Liljevallia gotlandica Hedström are described for the first time, and it is shown that both these species could also live ambitopically. The lower Wenlock Scamnomena rugata (Lindström) represents young individuals of the ambitopic variant of Leptaenoidea silurica, and is placed in synonymy, resulting in the valid name for the taxon being Leptaenoidea rugata. The range of this species now spans the whole Wenlock, from the upper Visby Formation to the Klinteberg Formation, and possibly even into the Ludlow. Ambitopic gerontic specimens of L. rugata develop very thick shells, in which the ventral valves have strong curvature, and become deeper not by geniculation but by successive mantle retractions and subsequent re-growth, in a way similar to that of atrypides. This shape was probably an adaptation to “floating” on softer substrates. The thickened gerontic dorsal valves have well-developed lophophoral support, showing the shape of the lophophore, which comprises two branches that curve inwards and then backwards; the lophophore was probably ptycholophous and similar to that in living members of the Thecideidina. Ambitopic specimens of Liljevallia could grow to a much larger size than cementing forms, where the dorsal valves have very large, posterior-facing cardinal process lobes and deeply impressed muscle fields and anterior scars. The presence of a ventral process and long, posteroventrally elongated cardinal process lobes, and the absence of dental plates reveals that Liljevallia was probably an early member of the Douvillinidae and is thus removed from the Leptaenoideidae.
|
|
| 3. |
- Streng, Michael, et al.
(author)
-
New and poorly known acrotretid brachiopods (Class Lingulata) from the Cedaria-Crepicephalus zone (late Middle Cambrian) of the Great Basin, USA
- 2006
-
In: Geobios. - : Elsevier BV. - 0016-6995 .- 1777-5728. ; 39:1, s. 125-154
-
Journal article (peer-reviewed)abstract
- Seven new late Middle Cambrian (Cedaria-Crepicephalus zone) acrotretid species are described from the Great Basin, USA. The species belong to five genera of which Lensotreta is new. The following new species are described: Anabolotreta? glabra, Anabolotreta mogota, Canthylotreta crista, Dactylotreta elegantula, Lensotreta perplexa, Opisthotreta transversa, and Opisthotreta indistincta. The shell structure of Canthylotreta is described for the first time based on new material of the type species Canthylotreta marjumensis and of the new species C. crista. The shell of Canthylotreta includes two types of shell fabric, camerate and columnar. Moreover, parts of the shell show transitional textures, supporting the view that the camerate shell structure may has originated from a columnar fabric. Picnotreta lophocracenta Robson and Pratt, 2001, recently described from western Newfoundland, is also described from the new occurrence in the Great Basin.
|
|
| 4. |
- Turner, Alan, et al.
(author)
-
Taxonomy and evolutionary patterns in the fossil Hyaenidae of Europe
- 2008
-
In: Geobios. - : Elsevier BV. - 0016-6995 .- 1777-5728. ; 41, s. 677-687
-
Journal article (peer-reviewed)abstract
- We review the larger pattern of appearance of the Hyaenidae in Europe and outline their part in the turnover of the guild of larger Carnivora that occurs across the Miocene–Pliocene boundary. The earliest record of the family is in MN4, although the patchy nature of the earliest records makes it difficult to be certain about the continent of origin. There is a clear pattern of morphological evolution over that long timespan, from the earliest viverrid- and herpestid-like forms through dog-like and more cursorial taxa to the larger, bone-crunching animals of the later Miocene and the Pliocene–Pleistocene epochs. Miocene dog-like hyaenas may indicate that social hunting had emerged by that time, while the appearance of larger species means that hyaena-accumulated bone assemblages may potentially occur in any late Miocene to Pleistocene locality.
|
|
| 5. |
- Zhang, Zhifei, et al.
(author)
-
Architecture and function of the lophophore in the problematic brachiopod Heliomedusa orienta (Early Cambrian, South China)
- 2009
-
In: Geobios. - : Elsevier BV. - 0016-6995 .- 1777-5728. ; 42:5, s. 649-661
-
Journal article (peer-reviewed)abstract
- The detailed structure of the lophophore is a key diagnostic character in the definition of higher brachiopod taxa. The problematic Heliomedusa orienta Sun and Hou, from the Lower Cambrian Chengjiang Lagerstatte of Yunnan, southwestern China, has a well-preserved lophophore, which is unlike that of any known extant or extinct brachiopods. Based on a comparative study of lophophore disposition in H. orienta and the extant discinid Pelagodiscus atlanticus, the in- and excurrent pattern and shell orientation of H. orienta are described and discussed. Reconstructions of lophophore shape and function are based on numerous specimens and comparison with P. atlanticus. The lophophore is composed of a pair of lophophoral arms that freely arch posteriorly rather than coiling anteriorly as commonly seen in fossil and recent lingulids. The lophophore is attached to the dorsal lobe of the mantle; it has neither calcareous nor chitinous supporting structures, and is disposed symmetrically on either side of the valve midline. The mouth can be inferred to be located at the base of the two brachial tubes, slightly posterior to the anterodorsal projection of the body wall. The lophophoral arms bear laterofrontal tentacles with a double row of cilia along their lateral edge, as in extant lingulid brachiopods. The main brachial axes are also ciliated, which presumably facilitated transport of mucous-bound nutrient particles to the mouth. The unique organization of the lophophore in Heliomedusa is not like any known fossil and living brachiopods. This clearly demonstrates that H. orienta is not a member of any crown group. It is here considered as a member of the brachiopod stem group, which challenges recent interpretations of a close discinid affinity. (C) 2009 Elsevier Masson SAS. All rights reserved.
|
|
| 6. |
|
|
| 7. |
- Gamez Vintaned, Jose Antonio, et al.
(author)
-
Trace and soft body fossils from the Pedroche Formation (Ovetian, Lower Cambrian of the Sierra de Cordoba, S Spain) and their relation to the Pedroche event
- 2006
-
In: Geobios. - : Elsevier BV. - 0016-6995. ; 39:4, s. 443-468
-
Journal article (peer-reviewed)abstract
- The low Lower Cambrian rocks from the Sierra de Cordoba contain one of the best successions in Europe, which consists of well exposed mixed facies with abundant fossil assemblages showing long stratigraphical ranges throughout the Pedroche Formation. These assemblages include diverse Ovetian archaeocyaths, trilobites, small shelly fossils, calcimicrobes, trace fossils and stromatolites. Trace fossils are still poorly known, and thus they are the main objective of this work. Ichnological data are obtained from the Arroyo de Pedroche 1, Arroyo de Pedroche 2 and Puente de Hierro sections. Trace fossils include the ichnogenera Bergaueria, aff. Bilinichnus, Cochlichnus, aff. Cosmorhaphe?, Cylindrichnus, Dactyloidites, Dimorphichnus, Diplichnites, Monocraterion, Palaeophycus, aff. Phycodes, Planolites, Psammichnites, Rusophycus, Skolithos, Torrowangea and Treptichnus, as well as faecal pellets, meniscate trace fossils and others. They are abundant in shales and sandstones, and indicate important changes in the benthic conditions with respect to the underlying Torrearboles Formation. Changes in fossil assemblages within Member I of the Pedroche Formation indicate palaeoccological disruptions, which led to the disappearance of numerous archaeocyath species and the decrease of stromatolite biodiversity. This was followed by dominance of trilobite and brachiopod assemblages, accompanied by trace fossils of the Psammichnites ichnosp. A ichnoassociation. This biotic turnover (Pedroche event) occurred at the lower part of the archaeocyath Zone III, within the Bigotina bivallata biozone. The diagnoses of the ichnospecies Cochlichnus anguineus and Dactyloidites cabanasi are emended. (c) 2006 Elsevier SAS. All rights reserved.
|
|
| 8. |
- Lindgren, Johan, et al.
(author)
-
Theropod dinosaur teeth from the lowermost Cretaceous Rabekke Formation on Bornholm, Denmark
- 2008
-
In: Geobios. - : Elsevier BV. - 0016-6995. ; 41:2, s. 253-262
-
Journal article (peer-reviewed)abstract
- The dinosaur fauna of the palynologically dated lower Berriasian Skyttegard Member of the Rabekke Formation on the Baltic island of Bornholm, Denmark, is represented by isolated tooth crowns. The assemblage is restricted to small maniraptoran theropods, assigned to the Dromaeosauridae incertae sedis and Maniraptora incertae sedis. The dromaeosaurid teeth are characterized by their labiolingually compressed and distally curved crowns that are each equipped with a lingually flexed mesial carina and a distinctly denticulated distal cutting edge. A morphologically aberrant tooth crown (referred to as Maniraptora incertae sedis) has triangular denticles of uneven width, a feature occasionally found in Upper Cretaceous hesperornithiform toothed diving birds, but also in premaxillary teeth of the velociraptorine Nuthetes from the Lower Cretaceous of England.
|
|
