Scientific Illustration

“The cetacean section of the composite phylogenetic hypothesis for Artiodactyla. Thickened colored bars above branches (D–Z and a–j) mark optimizations of various evolutionary changes within Cetacea (see Table 1). The three S = F symbols (blue and brown) are positioned on branches where parallel moves from saltwater to freshwater environments are inferred in the river dolphins – Inia, Lipotes, and Platanista. Thick branches connect extant taxa in the tree, and thin branches represent extinct lineages. The small, inset tree delimits (in gray) the section of the overall composite topology (Fig. 7) that is shown here at a larger scale. Approximate evolutionary time-scale, in millions of years, is at the base of the figure. For the mysticete section of the tree, one of the six minimum length trees derived from the Mysticeti supermatrix is shown. Relationships derived from the Artiodactyla supermatrix (stem Cetacea) 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)

“The non-cetacean section of the composite phylogenetic hypothesis for Artiodactyla. Thickened colored bars above branches (A–C) mark optimizations of various evolutionary changes on the lineage that leads to Cetacea (see Table 1). Gray bars above branches (1–3) indicate character state changes that are interpreted as convergences between early stem whales (see Fig. 9) and mesonychians. Thick branches connect extant taxa in the tree, and thin branches represent extinct lineages. The small, inset tree delimits (in gray) the section of the overall composite topology (Fig. 7) that is shown here at a larger scale. Approximate evolutionary time-scale, in millions of years, is at the base of the figure. Relationships derived from the Artiodactyla supermatrix are based on a strict consensus of trees. Artwork is by Carl Buell.”

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)

griseus:

Esquema que muestra la transición de un raoellido del Eoceno (A)  hasta los cetáceos del Eoceno / Oligoceno (B-H).

En orden Indohyus (Raoellidae, A), Pakicetus (Pakicetidae; B), Ambulocetus (Ambulocetidae; C), Remingtonocetus (Remingtonocetidae, D), Georgiacetus (Protocetidae, E), Dorudon (Basilosauridae, F), Janjucetus (Janjucetidae, Mysticeti; G) , y Aetiocetus (Aetiocetidae, Mysticeti, H)

Las ilustraciones están por Carl Buell. Paper en Science direct

“Phylogenetic relationships of extant Mysticeti (baleen whales) based on combined parsimony analysis of 23 datasets. Filter-feeding mode of each mysticete family is shown (A–C)”

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)

‘The phylogenetic position of Cetacea relative to other extant artiodactyls’

‘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)

“A phylogenetic blueprint for a modern whale (Balaenoptera musculus). The topology traces the inferred evolutionary history of an extant cetacean based on results summarized in Figs. 7–9 and Table 1. Changes extend back to the base of Artiodactyla (A–D). The long sequence of character transformations on the stem lineage to crown Cetacea (branches E–O), on the stem lineage to crown Mysticeti (branches a–f), and within crown Mysticeti (branches g–h) has culminated in the extant blue whale. A subset of the changes on these internal branches (Table 1) are marked by colored circles that indicate the internode where each character evolved and, when applicable, the approximate anatomical position of each derived character state (delayed transformation optimization): B-1 = three primary lung bronchi and multi-chambered stomach, B-2 = fibro-elastic penis with sparse cavernous tissue, C-1 = sparse hair, sebaceous glands absent, and transition to freshwater, C-2 = scrotum absent, can give birth underwater, and can nurse underwater, D = involucrum (thickening of medial wall of auditory bulla), E = robust tail, F–G = transition to saltwater, G = incisive foramina absent and vomeronasal organ inferred absent, H = short cervical (neck) vertebrae, K = posterior positioning of nasal aperture, L = no articulation between vertebrae and pelvis (sacroiliac joint absent), M1 = very short hindlimbs, M2 = tail flukes inferred present, O-1 = external ears absent, O-2 = immobile elbow joint, O-3 = sweat glands absent, a = broad rostrum, b = thin lateral margins of maxillae, c-1 = lateral nutrient foramina on palate and baleen inferred present, c-2 = unsutured mandibular symphysis, d = no teeth in adults, e-1 = telescoping of skull (anterior extension of occipital shield), e-2 = bowed mandibles, g-1 = fibrous temporomandibular joint, g-2 = muscle of tongue reduced (predominantly connective tissue) and ventral throat pouch with numerous grooves, h = enormous body size. Branch lengths are not proportional to time. 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) 

depictedscience:

Bernard-Germain de Lacépède: Oeuvres du Comte de Lacépède, comprenant l’histoire naturelle des quadrupèdes, des serpents, des poissons et des cétacés, Paris 1830.

(via depictedscience)

lostbeasts:

gallantcannibal:

Prehistoric whale evolution, illustrated by Tiffany Turrill.

Ambulocetus, my sweet baby

Whale fall communities of the deep sea - the Sulphophilic (sulphur loving) stage by Michael Rothman

“The time when the protagonists of stage of the opportunists begin to wane, because they consume all organic matter, is mainly a function of the size of the carcass and large cetaceans for the second stage can last up to several years. At this point the bones that remain on the bottom can still be exploited by new organisms that use energy as a source of fat contained in them: as you know the infamous whale hunters, in fact, up to 60% of the bones of a whale is made of lipids. The third stage Begins in which the bones, still rich in lipids, are attacked by anaerobic bacteria that transform the sulphate present in seawater in sulfides. The sulphides lead to the appearance, around the carcass, a new food chain based chemosynthetic, consists of both carpets of chemoautotrophic bacteria, both from molluscs with chemiosimbionts. The community of the sulphophilic stage is characterized by a wealth of species, many of which are abundant in the immediate vicinity of the bones, but rare in neighboring habitats.

After this stage researchers think that the bones can form a reef where the currents undergo a minor slowdown of friction with respect to the sea bed and therefore are a preferential area for filter feeders: crinoids, brittle stars and cnidarians have in fact been found by Japanese researchers on a carcass sank artificially. The reef stage ends the ecological succession.”

Text is a slightly edited Google translation of the source.

See also: Stage 1 & Stage 2

“The phylogenetic position of Cetacea relative to other extant mammals. Parsimony analysis of 26 nuclear loci (Goloboff weighting with k = 2) position Cetacea deep within Artiodactyla and distantly related to other obligately aquatic mammals (Sirenia). For the placements of aquatic mammals and for relationships among higher-level placental groups, circles at nodes indicate >90% bootstrap support. Branches are proportional to the number of substitutions optimized to branches; long basal branches with cross bars were truncated for aesthetics. The cladogram is rooted by vertebrate outgroups to Mammalia (Gallus, Taeniopygia, Anolis, Xenopus, Danio). Artwork is by Carl Buell.”

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)