Return to "Becoming Whales" Lesson

BECOMING WHALES
INDEX TO ILLUSTRATIONS
to print out and copy for classroom use

Whales in the Making: a page with 6 strips illustrating extinct early whale ancestors (skeletons and reconstructions), to be cut apart and used by student teams on their Eocene timeline, following the narrative sequence. (very sharp, 1.8 MB PDF file). For alternative page, taken from the Science Kit version (1.9 MB), Click Here. Each version has different features; just pick the one preferred to use.

Some Modern Whales: a page of 6 species of modern whales, in approximately comparable scale sizes (an optional item). Can be cut apart to place on classroom Cenozoic timeline, or used to make overhead transparency. (very sharp, 0.893 MB PDF file).

Pakicetus 2: an alternative reconstruction of Pakicetus (to the one shown on the "Whales in the Making" page. Can be used during class discussion of student discussion question #5.

Whale Family Tree: a current family tree (from Hans Thewissen's web site). Note that the early whale ancestors (archaeocetes) are NOT considered direct antecedants of modern whales, but rather as early offshoots ("cousins") reflecting stages of whale evolution during the Eocene.

Whale Phylogeny, and Osmoregulation page: possible relationships of whales to other living mammals, based on recent DNA analyses; note closeness to hippos, and no indication of relationship to the extinct mesonychid group (possibly more remote that previously thought).
Osmoregulation: analysis of Oxygen isotopes in bones and teeth of living and extinct whales indicates their typical habitats (freshwater vs seawater). Note Ambulocetus' fossils show wide range of water habitats, while earlier archaeocetes indicate freshwater habitat and later archaeoctes are associated with seawater habitat, consistent with anatomical analyses.

Continental Drift (Plate Tectonics) and the Tethys Sea, in 5 stages over the past 250 million years, showing how India (in red) was carried toward Asia and "crashed" into it (an, in fact, still crunhing into Asia, raising the Himalaya mountains). Also, see a more detailed view of India "rafting" towards Asia over the past 71 million years, making the ancient Tethys Sea more and more shallow, therefore warmer, with richer food supply, creating long-term selective pressure favoring the evolution of aquatic mammals in the region. There's also an excellent video animation showing (with sound effects) this plate movement in cross-section. The India-rafting figure and the video animation both come f rom The Geological Society

Map of Whale Fossil Sites in Pakistan & Afghanistan: (shown in red, on green background). These are exposures of Eocene sediments, pushed up byt the snails-paced scrunching of India into Asia. This map was accessed through the now closed site of whale-fossil specialist Hans Thewissen.