Early Ordovician Bivalve Radiations and Their Cause
نویسندگان
چکیده
منابع مشابه
Burrowers from the Past: Mitochondrial Signatures of Ordovician Bivalve Infaunalization
Bivalves and gastropods are the two largest classes of extant molluscs. Despite sharing a huge number of features, they do not share a key ecological one: gastropods are essentially epibenthic, while most bivalves are infaunal. However, this is not the ancestral bivalve condition; Cambrian forms were surface crawlers and only during the Ordovician a fundamental infaunalization process took plac...
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There are two ways eukaryotes double number of chromosomes: (1) whole genome duplication (polyploidy), in which all nuclear DNA is replicated, and (2) karyotypic fission (pseudopolyploidy), in which all chromosomes are physically bifurcated. We contrast polyploidy with pseudopolyploidy, highlighting when it is crucial to look at genetic vs. genomic levels. We review history of pseudopolyploidy,...
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BACKGROUND Bivalves are very ancient and successful conchiferan mollusks (both in terms of species number and geographical distribution). Despite their importance in marine biota, their deep phylogenetic relationships were scarcely investigated from a molecular perspective, whereas much valuable work has been done on taxonomy, as well as phylogeny, of lower taxa. METHODOLOGY/PRINCIPAL FINDING...
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Understanding ancient climate changes is hampered by the inability to disentangle trends in ocean temperature from trends in continental ice volume. We used carbonate "clumped" isotope paleothermometry to constrain ocean temperatures, and thereby estimate ice volumes, through the Late Ordovician-Early Silurian glaciation. We find tropical ocean temperatures of 32° to 37°C except for short-lived...
متن کاملPalaeogeography and palaeoecology of early Floian (Early Ordovician) cephalopods from the Upper Fezouata Formation, AntiAtlas, Morocco
This is the first description of Ordovician cephalopods from Morocco. Although their occurrence has been known for a long time, only a poorly preserved conch from the late Katian of Ikhf n’Ouzerg (central Anti-Atlas) was described as “Orthoceras hastile Barrande” by Termier & Termier (1950). In some cases Ordovician cephalopods were mentioned within faunal lists without classification (e.g., Gu...
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ژورنال
عنوان ژورنال: The Paleontological Society Special Publications
سال: 1996
ISSN: 2475-2622,2475-2681
DOI: 10.1017/s247526220000085x