Le cachalot (Physeter macrocephalus) Guide des mammifères marins, Delachaux
"A composite phylogenetic hypothesis for Artiodactyla, including Cetacea. The overall tree is the result of merging topologies derived from supermatrix analyses of three concatenated datasets that include molecular, phenotypic, and fossil information: Mysticeti (Deméré et al., 2008; this study), crown Cetacea (Geisler et al., 2011), and Artiodactyla (Geisler et al., 2007; Spaulding et al., 2009; this study). Thick branches connect extant taxa in the tree, and thin branches represent extinct lineages. Brackets to the right delimit clades and stem groups to crown clades; the small, inset tree delimits Cetacea (blue) and Artiodactyla (yellow). Approximate evolutionary time-scale, in millions of years, is at the base of the figure (see Section 2 for basis). For the mysticete section of the composite tree, one of the six minimum length trees derived from the Mysticeti supermatrix is shown here. Relationships derived from the Artiodactyla supermatrix (stem Cetacea, basal artiodactyl relationships, outgroups) and from the crown Cetacea supermatrix (Odontoceti) are based on strict consensus trees. Artwork is by Carl Buell. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)"
A phylogenetic blueprint for a modern whale. Gatesy J, Geisler JH, Chang J, Buell C, Berta A, Meredith RW, Springer MS, McGowen MR. Mol Phylogenet Evol. 2012 Oct 26. pii: S1055-7903(12)00418-6. doi: 10.1016/j.ympev.2012.10.012. (pdf)
Too often Basilosaurus is reconstructed as a shrink-wrapped snake-monster, so I attempted to portray it more in line with modern cetaceans. I started with Kellogg’s 1936 B. cetoides and added 10 more vertebrae, since complete B. isis specimens suggest his reconstruction was probably too short. When confronted with long spinal columns, lots of reconstructions get bored and let them wander around, but instead I used the Woods Hole CSI website as a resource to align the vertebrae in a plausible way. The website also proved invaluable when giving Basilosaurus a proper coating of soft tissue, including determining a plausible placement for the dorsal fin. Basilosaurus lacked the caudal peduncle of modern cetaceans — an area with no transverse processes prior to the flukes — so I decided to give it a more paddle-like tail. Of course, this is undoubtedly far too conservative and Basilosaurus probably had some weirdness that couldn’t be predicted from the bones.
A sperm whale’s head is actually an oversized nose (which in mature males can make up a third of the animal’s body!). Sperm whales use their uniquely shaped nose to generate sound. Here’s how.
© AMNH/5W Infographics
Blue Whale anatomy
Thanks for the submission Emma!
From Whales by Robert Hamilton (1843)
Bowhead whale (Balaena mysticetus) with polar bear (Ursus maritimus) for scale
by Carl Buell
Bowhead whale paiting by Carl Buell