Web22. 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 ... Web25. sep 2024 · In petalichthyids such as Eurycaraspis, the overlapped area is well defined laterally from the rest of the skull roof and is named the posterior descending lamina. (8) Presence or absence of a lateral ridge or process (mesial articular process in [ 48 ]) defines the mesial boundary of the visceral contact face for the articular lamina on the ...

Further petalichthyid remains (placoderm fishes, Early

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 export of defense articles

Chondrichthyan - Evolution Britannica

Web27. 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 ... Web1. feb 2015 · Outside China, petalichthyids are known from the Emsian (Early Devonian) to the Late Frasnian (Late Devonian), and belong to the Macropetalichthyidae exclusively. … WebThe petalichthyids are placoderm-grade stem-group gnathostomes known from both isolated skeletal material and rarer articulated specimens of one genus. They are of … bubbles powerpuff bubble wand