Petalichthyids
Web10. sep 2024 · The petalichthyids are placoderm-grade stem-group gnathostomes known from both isolated skeletal material and rarer articulated specimens of one genus. Web3. apr 2010 · Some fresh water needlefishes reach only 6 or 7 cm in total length while some marine species may attain 2 m. Composition of Family: The Belonidae contains 10 genera and 34 species. Four genera are monotypic: the southern African Petalichthys, the worldwide Ablennes and Platybelone, and apparently the Asian freshwater Xenetodon. …
Petalichthyids
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Web10. sep 2024 · Abstract. Petalichthyid and “acanthothoracid” placoderms have taken pivotal positions in the debate on placoderm — and, by extension, jawed vertebrate — … Web5. feb 2024 · The petalichthyids are placoderm-grade stem-group gnathostomes known from both isolated skeletal material and rarer articulated specimens of one genus.
WebThe Early Devonian petalichthyid Diandongpetalichthys is revised on new material and the phylogenetie position of the genus is confirmed. Being the oldest petalichthyid known so far, Diandongpetalichthys shows some primitive character states which are compared with those of the primitive arthrodires to throw new light on the understanding of the … WebThe petalichthyids are placoderm-grade stem-group gnathostomes known from both isolated skeletal material and rarer articulated specimens of one genus. They are of …
WebThis page was last edited on 15 January 2024, at 08:59. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply.By ... Petalichthyida is an extinct order of small, flattened placoderm fish. They are typified by their splayed pectoral fins, exaggerated lateral spines, flattened bodies, and numerous tubercles that decorated all of the plates and scales of their armor. They reached a peak in diversity during the Early Devonian and were … Zobraziť viac According to Zhu's 1991 redescription of Diandongpetalichthys, that genus represents the most basal petalichthyid known, as it has a comparatively elongated head, and shares certain anatomical … Zobraziť viac • Long, John A. The Rise of Fishes: 500 Million Years of Evolution Baltimore: The Johns Hopkins University Press, 1996. ISBN 0-8018-5438-5 • Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Placodermi entry)". Bulletins of … Zobraziť viac
WebThe family contains two confirmed genera, Quasipetalichthys, and Eurycaraspis, which differ from the more advanced macropetalichthyids by having more squared skulls that have …
Weblepids or petalichthyids. A complete canal commissure between the centers of ossification of the centrals appears to be present in at least some specimens of Coccosteus decipiens (Heintz, 1931, fig. 2) and C. fletti (Watson, 1932, fig. 1). In addi-tion, a canal extends medially from the center of ossification of the central in at least thin islandWeb158 As in many petalichthyids (Stensiö 1925, 1969, Young 1978) the posterior and occipital portion 159 of the braincase is more strongly mineralised, while the orbital and antorbital regions are 160 incompletely mineralised. 161 Orbital region 162 The orbits are dorsolaterally oriented (Figs. 1A, 1B, 2), as in other petalichthyids. Only the thinist adult diaperWeb27. nov 2008 · These features are regarded as primitive for petalichthyids. A new restoration shows the glenoid processes and foramen magnum to be similarly developed to Kujdanowiaspis, but the high position of the lateral line canal and the absence of a preserved anterior dorsolateral plate preclude an adequate functional interpretation of the neck-joint ... salesforce badge iconsWeb13. mar 2024 · The presence of Diandongpetalichthys, along with other primitive petalichthyids including Neopetalichthys and Quasipetalichthys, and more advanced petalichthyids, suggest that the order may have arisen … thinist edc beltWebPossibly their precursors were the petalichthyids, a group of Devonian sharklike placoderms that had ossified skeletons and well-developed fins. The phyletic relationship of the … thin italian breadstickWeb22. apr 2015 · Likewise, it suggests that the similarities between the more flat-headed and presumably benthic placoderms, such as antiarchs and petalichthyids, and jawless outgroups reflect a shared primitive ... thin items in a brushWeb5. okt 2024 · The dorsoventrally flattened body shape, the terminal mouth and anterodorsal eyes of the antiarchs, rhenanids, phyllolepids and petalichthyids indicated that these were bottom dwellers. The rhenanids had enlarged, semicircular ray-like pectoral fins which, and they either undulated or oscillated to achieve propulsion. salesforce banking projects