Woodward Original Early Drawing of Devonian Marine Life

WOODWARD, Alice B. (1862-1951).
Devonian Marine Life (Coccosteus, Blastoid, Ostracoderm, Terataspis, Ammonoid, Pterichthys, Pephricaris, Proetus).
Original Illustration in pen, ink and grey wash, heightened in white.
c.1905-1912.
10 3/4" x 7 5/8" sheet.

Original artwork for Henry R. Knipe's "Evolution in the Past". Illustrated on page 38.

1. Coccosteus ("seed bone") is an extinct genus of arthrodire placoderm. Its fossils have been found throughout Europe and North America. The majority of these have been found in freshwater sediments, though, such a large range suggests that they may have been able to enter saltwater. The largest specimens were about 40 centimeters (16 in), although the average length was 20 to 24 centimeters (7.9 to 9.4 in).

2. Blastoids (class Blastoidea) are an extinct type of stemmed echinoderm, often referred to as sea buds.[1] They first appear, along with many other echinoderm classes, in the Ordovician period, and reached their greatest diversity in the Mississippian subperiod of the Carboniferous period. However, blastoids may have originated in the Cambrian. Blastoids persisted until their extinction at the end of Permian, about 250 million years ago. Although never as diverse as their contemporary relatives, the crinoids, blastoids are common fossils, especially in many Mississippian-age rocks.

3. Ostracoderms (lit. 'shell-skins') are the armored jawless fish of the Paleozoic Era. The term does not often appear in classifications today because it is paraphyletic or polyphyletic, and thus does not correspond to one evolutionary lineage. However, the term is still used as an informal way of loosely grouping together the armored jawless fishes. After the appearance of jawed fish (placoderms, acanthodians, sharks, etc.) about 420 million years ago, most ostracoderm species underwent a decline, and the last ostracoderms became extinct at the end of the Devonian period. More recent research indicates, however, that fish with jaws had far less to do with the extinction of the ostracoderms than previously assumed, as they coexisted without noticeable decline for about 30 million years.

4. Terataspis is a comparatively huge, 60 centimeter long lichid trilobite genus from the Early Devonian, about 397 million years ago. It lived in a shallow sea in what is now New York State and Ontario. No whole specimens have been found, only disarticulated fragments of its exoskeleton, but enough fragments have been found to allow researchers to form reconstructions of the whole animal. The genus only contains one species, T. grandis, which, like many other trilobites, was presumed to have been a detritivore that was also an opportunistic predator, preying on small burrowing animals, such as mollusks, worms, or arthropods.

5. Ammonoids are a group of extinct marine mollusk animals in the subclass Ammonoidea of the class Cephalopoda. These mollusks, commonly referred to as ammonites, are more closely related to living coleoids (i.e., octopuses, squid, and cuttlefish) than they are to shelled nautiloids such as the living Nautilus species. The earliest ammonites appear during the Devonian, and the last species vanished in the Cretaceous–Paleogene extinction event.

6. Pterichthyodes is a genus of antiarch placoderm fishes from the Devonian period. Its fossils have been discovered in Scotland. They were one of the first species recognized for what they were, as their fossils are common in the Old Red Sandstone formation studied by geologists in the early 19th century. Due to their extreme divergence from modern-day fish, they were a puzzle unsolved until Charles Darwin brought forward his theories on evolution.

7. Pephricaris is an extinct genus of crustaceans from the class of the Malacostraca (higher crustaceans).

8. Proetus is a genus of proetid trilobite found in Silurian-aged marine strata of Europe. The generic name commemorates Proetus (Greek: Προῖτος), a mythical king of Argos and Tiryns, son of King Abas of Argo. Proetus is the type genus of the order Proetida, and of the family Proetidae. The genus became a wastebasket taxon that held numerous species of similar looking trilobites from the Ordovician to Carboniferous periods. Most of these species have been split off into other genera, leaving only P. concinnus and P. latifrons as the only confirmed members. Fossils of the type species, P. concinnus, are found in Wenlock-aged marine strata of Sweden, Great Britain, Estonia, and Germany. Fossils of the other recognized species, P. latifrons, are found in Llandovery-aged marine strata of Ireland and Great Britain.