Viviparity in " Incisoscutum " and the ptyctodontids show that these placoderms were the first K-strategists in relation to breeding.
42.
Despite the original interpretation presented by Denison in 1941, not all paleontologists agree that placoderms like " Bothriolepis " actually possessed lungs.
43.
Spiny sharks were another class of fish which appeared also in the fossil records during the Silurian at about the same time as the placoderms.
44.
In the early middle Devonian ( 416-385 Ma ), while the predatory placoderms dominated the seas, some sarcopterygians came into freshwater habitats.
45.
The various groups of placoderms were diverse and abundant during the Devonian, but became extinct at the end-Devonian Hangenberg event 360 million years ago
46.
The earliest antiarch placoderms first appeared in the Silurian period of the Paleozoic Era and could be found distributed on every continent by the Devonian period.
47.
The placoderm " Brindabellaspis stensioi " was once regarded as a weejasperaspid because of the similarities between its dermal plates to the other weejasperaspids.
48.
The ptyctodontid fishes are the only group of placoderms to display sexual dimorphism, where males have clasping organs and females have smooth pelvic fin bases.
49.
McLennegan s reason for studying the lake is for its remarkable property of prehistoric life washing ashore, such as tree-like ferns and placoderms.
50.
""'Potangaspis " "'is an extinct genus of placoderm fish which existed in China during the Devonian period.
