Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
1,584 result(s) for "Paleontological Notes"
Sort by:
Carnivora from the Late Early Pleistocene of Cal Guardiola (Terrassa, Vallès-Penedès Basin, Catalonia, Spain)
The paleontological site of Cal Guardiola (UTM 31T DG1702), on the western bank of the Torrent de Vallparadís (Terrassa, Catalonia, Spain), was discovered in early 1997 during the construction of a socio-sanitary building next to the Mútua de Terrassa. A report on the geology and stratigraphy of Cal Guardiola was published by Berástegui et al. (2000), including a preliminary report on the fauna. This preliminary study suggested an estimated age for Cal Guardiola of ca. 1.0 Ma (Berástegui et al., 2000). Unpublished paleomagnetic analyses, carried out by Miguel Garcés, indicate a reverse magnetization for the sampled sediments, which can be correlated to below the Brunhes-Matuyama geomagnetic boundary (pers. com. of M. Garcés in Postigo Mijarra et al., 2007), thus being older than 0.8 Ma. This dating roughly corresponds to the later part of the Epivillafranchian biochron (1.2 to 0.9 Ma), which in Europe is best represented by the faunal assemblages from Untermassfeld in Germany, Le Vallonnet in France, and Colle Curti and Slivia in Italy (Palombo et al., 2008 and references therein). The faunal assemblage from Cal Guardiola represents one of the latest Epivillafranchian faunas from Europe and thus deserves particular attention for unraveling the chronology of the dispersal events that took place during the Epivillafranchian-Galerian turnover. However, thus far only the primate remains from Cal Guardiola have been published (Alba et al., 2008), while the rest of the fauna remains unpublished. Here we describe the carnivore remains from Cal Guardiola, which record one of the latest occurrences of the hyenid Pachycrocuta in Europe and further attests the coexistence of two distinct ursid lineages by the latest Early Pleistocene in Europe.
Earliest North American Occurrence of Polycotylidae (Sauropterygia: Plesiosauria) from the Lower Cretaceous (Albian) Clearwater Formation, Alberta, Canada
The polycotylidae is a family of short-necked (pliosauromorph) plesiosaurs, with examples known from epicontinental marine deposits of every major landmass except Antarctica. Our knowledge of its diversity and distribution has increased tremendously in the last decade, with new material described from North America (Sato, 2005; Albright et al., 2007; Schumacher, 2007; Schmeisser, 2008), South America (Gasparini and de la Fuente, 2000; Salgado et al., 2007), Africa (Bardet et al., 2003; Buchy et al., 2005), and Asia (Sato and Storrs, 2000; Arkhangel'skii et al., 2007). Polycotylid diversity is greatest in the Late Cretaceous, and particularly so in the Turonian; however, knowledge of the group's initial history in the Early Cretaceous is limited to a handful of specimens from North America (Storrs, 1981; Druckenmiller, 2002) and Australia (Kear 2003, 2005).
A Panorpoid (Insecta: Mecoptera) from the Lower Eocene of Patagonia, Argentina
The order Mecoptera is represented on all continents, albeit with an uneven distribution. Mecoptera includes about 34 families (Labandeira, 1994, p. 34), only four of them, until now, represented in South America: Permochoristidae Tillyard, 1917 (†) (Pinto, 1972); Bittacidae Handlirsch, 1906 [and stem-group “Neorthophlebinae” (†)] (Petrulevičius, 2001a, 2003, 2007); Nannochoristidae Tillyard, 1917; and Eomeropidae Cockerell, 1909. The two latter families have a present relict distribution in southern South America but without fossil record, obviously an artifact due to few studies of fossil insects in the subcontinent. The diversity of recent Bittacidae is high in South America with respect to other continents. Thirty-five percent of recent genera of Bittacidae come from South America, and 80% of these genera are endemic (extracted from Penny, 1997). Bittacidae is well represented in the fossil record, with species from the Jurassic of Patagonia (Petrulevičius, 2007), Lower Cretaceous of Brazil (Petrulevičius and Martins-Neto, 2001), to the late Paleocene of Argentina (Petrulevičius, 1998, 1999, 2001b, 2003). This contribution reports a specimen belonging to the Panorpoidea, a group with no recent species in South America and very few species in the entire Southern Hemisphere.
The Tropical Tortoise Chelonoidis denticulata (Testudines: Testudinidae) from the Late Pleistocene of Argentina and Its Paleoclimatological Implications
The terrestrial tortoise clade Chelonoidis is endemic to the South American continent and nearby islands. Three continental species are currently recognized that inhabit three distinct habitats. The red-footed tortoise (C. carbonaria) and yellow-footed tortoise (C. denticulata) are often sympatric tropical to semi-tropical taxa, but the former taxon generally prefers open and wet savannahs, whereas the latter distinctly prefers permanent and wet forest cover. In contrast, the Chaco Tortoise, C. chilensis, is arid-adapted and lives along the eastern dry slopes of the southern Andes (Ernst and Barbour, 1989). The diverse group of generally dry-adapted tortoises from the Galapagos Islands is currently thought to be the gigantic sisters of C. chilensis (Caccone et al., 1999).
First Definite Record of Permian Edrioasteroids: Neoisorophusella maslennikovi n. sp. from the Kungurian of Northeast Russia
The late history of edrioasteroids has come to light only in the last 40 yr. When the edrioasteroid chapter of the Treatise on Invertebrate Paleontology was published (Regnéll, 1966) the youngest known edrioasteroids were upper Mississippian (Chesterian). Since that time, a series of papers have described edrioasteroids in the Pennsylvanian (Fraunfelter and Utgaard, 1970; Bell, 1976; Sumrall, 1992; Sumrall and Bowsher, 1996; Sumrall et al, 2000, 2006). Pennsylvanian edrioasteroids now include nine species distributed among six genera, including one fauna bearing four genera (Sumrall et al., 2006). These edrioasteroids are not limited to a single clade but include postibullinids, plesiomorphic agelacrinitids, and derived clavate discocystinids.
Ontogeny of the Middle Cambrian Trilobite Shantungia spinifera Walcott, 1905 from North China and Its Taxonomic Significance
The Cambrian trilobite Shantungia Walcott, 1905 is a monotypic genus, with S. spinifera Walcott, 1905 as the genotype and is characterized by its long frontal spine extending medially from the anterior cranidial border. The genus has hitherto been known restricted in occurrence to the traditional Drepanura Zone of North China (Walcott, 1913; Endo and Resser, 1937; Qiu et al., 1983; Zhang and Jell, 1987). As Drepanura Bergeron, 1899 is preoccupied by a collembolan insect and Neodrepanura Özdikmen, 2006 was proposed as a replacement, this zone is referred to as the Neodrepanura Biozone herein.
Re-Description and Neotypification of Archamphiroa jurassica Steinmann 1930, a Calcareous Red Alga from the Jurassic of Argentina
Archamphiroa jurassica was described by Steinmann (1930) from carbonate deposits of the Cordillera de los Andes in Mendoza, central Argentina (Arroyo Negro, confluent of Malargüe River), assigned to the Callovian stage. Based on the general morphology and the internal structure of the identified fragments, Steinmann considered them to belong to the coralline algae. Comparisons made with some fossil and extant corallines species led him to the conclusion that Archamphiroa jurassica closely resembles some species of the extant genus Amphiroa.
The oldest-known metazoan parasite?
A unique specimen of the micromorphic fossil lingulate (organophosphatic-shelled) brachiopod Linnarssonia constans Koneva, 1983 from the late Lower Cambrian Shabakty Group of the Malyi Karatau Range in Kazakhstan, Central Asia, preserves evidence of infestation within the mantle cavity by a vermiform animal, leading to the growth of an internal tubular protuberance (Fig. 1) resulting from symbiosis some 520 million years ago. Examples of symbiotic relationships between metazoans in the early Paleozoic are sparse (Conway Morris, 1981, 1990; Conway Morris and Crompton, 1982). Descriptions of a variety of galls and tumorlike swellings in some trilobites extend records back to the Middle Cambrian (Conway Morris, 1990), but their interpretation as traces of endoparasitic activity remains somewhat speculative. Thus galllike swellings on the stems of Silurian echinoderms (Franzen, 1974), vermiform tubes on some early Ordovician dendroid graptolites (Conway Morris, 1990), and various tubes and blisters on graptoloid graptolites (see Bates and Loydell, 2000 for review) are among the hitherto earliest known convincing records of host-parasite relationships within metazoans. Our example reported here predates the oldest of these previous records by approximately 35 to 40 million years, and demonstrates that symbiosis involving complex adaptations (e.g., larval settlement on or within living tissue and exploitation of feeding systems of the host) and codependent life cycles were already established soon after the ‘explosive’ evolutionary radiation of marine metazoans in the early Cambrian. The fossil evidence of infestation on lophophorates is especially sparse, at best. The oldest hitherto undoubted records are both from brachiopods of Devonian age, in the Lower Devonian Emsian Stage of eastern Australia and in the Middle Devonian Givetian Stage of the Holy Cross Mountains in Poland, respectively.
Permian Hyolithida from Australia: the last of the hyoliths?
Class Hyolitha Marek, 1963 encompassing the Order Hyolithida Sysoev, 1957 (Early Cambrian to Upper Permian) and Order Orthothecida Marek, 1966 (Early Cambrian to Early Devonian) consists of a group of conical, calcareous-shelled invertebrates of controversial affinity. One opponent view holds that hyoliths may be reasonably accommodated under the Phylum Mollusca (Malinky and Yochelson, 2007 and references therein), whereas another supports separate phylum status under the name Hyolitha (Pojeta, 1987 and references therein). Hyolith abundance and diversity attain a maximum in the Cambrian, followed by a progressive decline up to their Permian extinction (Fisher, 1962; Wills, 1993). Their demise was part of the extinction event of the Late PermianlEarly Triassic. The cause(s) of this event remains controversial (Erwin et al., 2002), and no imprint remains in the geologic record of the specific circumstances surrounding the disappearance of the hyoliths, though it is highly probable that reduced population size was a contributing factor. Given the overall rarity of Late Paleozoic hyoliths, every occurrence is worthy of note to better understand patterns of hyolith diversity and abundance in the Late Paleozoic, the geographic and stratigraphic distribution of hyolith taxa and circumstances related to their extinction. The species from the Upper Permian described herein is among the youngest, if not the youngest, members of class Hyolitha.
The youngest cambroclaves: Cambroclavus absonus from the Middle Cambrian of the Cantabrian Zone (northwest Spain)
Cambroclayes are Cambrian phosphatized problematica. The group is known from spine-like remains that are locally abundant on a number of Cambrian paleocontinents. Cambroclaves are known through a relatively short time interval (late Early Cambrian-early Middle Cambrian) mostly from tropical, carbonate platform successions on the Siberian Platform, East Gondwana (Australia, China, Kazakhstan), and West Gondwana. The West Gondwana occurrences include Cambroclavus ludwigsdorfensis Elicki, 1994 and Cambroclavus sp. from the late Early Cambrian of eastern Germany (Elicki, 1994, 2005; Elicki and Watte, 2003), and Cambroclavus sp. from the early Middle Cambrian of Sardinia (Elicki and Wotte, 2003;“ Elicki et al., 2003; Elicki, 2005, 2006). Recently, Clausen and Alvaro (2006) reported the zhijinitid form Parazhijinites cf. guizhouensis Qian and Yin, 1984 from the early Middle Cambrian of the Cantabrian zone of northwest Spain. Other than the mentioned tropical occurrences, Landing (1991) published the obviously cool to cold water form Samsanoffoclavus matthewi Landing, 1991 from the middle Early Cambrian of Cape Breton Island (Avalonia).