Thesis (Ph.D) - University of Birmingham, School of Earth Sciences, Faculty of Science, 2001.
|Statement||by Karen Dawn Cochrane.|
|The Physical Object|
|Pagination||284 p. :|
|Number of Pages||284|
Chronology of early Cambrian biomineralization. Volume , Issue 2; On the evolution and histology of some Cambrian protoconodonts, paraconodonts and primitive euconodonts. Fossil embryos from the Middle and Late Cambrian Period of Hunan, south China. Nature , –Cited by: Quantitative paleoprovincialism is studied, using a coefficient of similarity (CS) formula. The results indicate that the provincialism of the late Middle through middle Late Cambrian paraconodonts and protoconodonts did exist. The provincialism of Ordovician conodonts can be traced back to late Middle Cambrian. The North China Province and South Cited by: 4. Previous reports on the morphological evolution of protoconodonts and paraconodonts are reviewed. The evolutionary trends exhibited by species of the protoconodont genus Gapparodus and the paraconodont genus Westergaadodina are discussed. Based on the present study on histology, genus Paibiconus is protoconodont, while genus Yongshunella is Cited by: 5. Middle and Upper Cambrian Protoconodonts and Paraconodonts from Hunan, South China Article (PDF Available) in Palaeontology 44(5) - November with 98 .
Geological history. The conodonts first appeared during the Cambrian Stage 2 (also referred as Tommotian). The still unnamed Cambrian Stage 10 can be defined as the first appearance of Eoconodontus upper boundary is defined as the appearance of Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is Class: †Conodonta, Eichenberg Euconodonts have long been an enigmatic group of fossil marine animals, represented by minute, comb-shaped or claw-shaped denticles - the 'conodonts' - which were widely used by stratigraphers for dating and correlating geological formations. They are known from the Middle Cambrian ( million years) to the Late Triassic ( million years). Conodonts are an extinct group of jawless vertebrates whose tooth-like elements are the earliest instance of a mineralized skeleton in the vertebrate lineage 1,2, inspiring the inCited by: However, if it is confirmed that protoconodonts are phylogenetically related to chaetognaths, and also confirmed that a phylogenetic relationship does exist between protoconodonts, paraconodonts and euconodonts (Vannier et al. , and references therein), the latter would also be related to chaetognaths, rather than to chordates, a hypothesis Cited by:
conodont (kō′nə-dŏnt′, kŏn′ə-) n. 1. Any of various small marine chordates of the group Conodonta of the Paleozoic Era and the Triassic Period, preserved primarily in the form of their conelike teeth. 2. A fossil tooth of this chordate. Conodonts are the most widespread Paleozoic microfossils and are important for biostratigraphic. The very earliest conodonts are known from rocks of probable Precambrian age in Siberia, they are found more commonly in Cambrian deposits, diversity increased in the Ordovician and again during the Devonian. The conodont-bearing organism clearly survived the Permo-Triassic boundary extinctions but became extinct during the late Triassic. Conodont, minute toothlike fossil composed of the mineral apatite (calcium phosphate); conodonts are among the most frequently occurring fossils in marine sedimentary rocks of Paleozoic age. Between mm ( inch) and 6 mm in length, they are known as microfossils and come from rocks ranging in age from the Cambrian Period to the end of the Triassic Period. Conodont definition is - a Paleozoic toothlike fossil that is probably the remains of an extinct eellike marine animal that may be an invertebrate or primitive vertebrate; also: the animal from which conodonts are derived.