Abstract
Abstract Stylophora (cornutes and mitrates) are controversial Paleozoic fossils, variously interpreted as ‘bizarre’echinoderms or as ‘calcichordates’ (primitive chordates). The calcichordate theory is based on the identification of left/right asymmetries supposed to be homologous in stylophorans and modern chordates. This theory imposes the homology of the plano-concave surface of the cornute test with the convex surface of the mitrate test. A detailed analysis of numerous internal and external structures exhibited by the appendage and the test demonstrates the homology of the plano-concave surface of the test in all stylophorans. The basic assumption of the calcichordate theory is thus not valid. Comparison of left/right asymmetries in these organisms with those of modem chordates is not grounded. Stylophora do not represent `calcichordates' but actual echinoderms.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
