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Foregut fermentation in mammals
Foregut fermentation is best known from the ruminants, such as cattle, deer and giraffes, that regurgitate and rechew their food to aid microbial digestion. However, they are not the only mammals to have evolved this digestive strategy...
Gliding mammals rely primarily on extensive skin membranes or ‘patagia’ that stretch between fore- and hind-limbs, creating a wing-like structure.
In the reptiles, different forms of skin membrane (called ‘patagia’) and in some extinct species, primitive feathers, have evolved convergently as adaptations for gliding.
Mammal-like placentation in skinks (and fish)
“Only two types of vertebrates [have] evolved a reproductive pattern in which the chorioallantoic placenta provides the nutrients for fetal development. One is [...] the eutherian mammals […], and the other, a few lineages of the family Scincidae.” A.F. Flemming (2003) J Exp Zool 299A 33-47
Viviparity in sauropterygians
“The [fossilised] embryos are mostly in articulation and their distribution on each side indicates that female Keichousaurus hui had a pair of oviducts as in ichthyosaurs and many extant lizards.” Y. Cheng et al. (2003) Nature vol. 432, p.383
Viviparity in mosasaurs
An exceptionally preserved gravid female of the aigalosaur Carsosaurus contains at least at least four advanced embryos […] Their orientation suggests that they were born tail-first […] to reduce the possibility of drowning, an adaptation shared with other other highly aquatic amniotes” M.W. Caldwell & M.S.Y. Lee (2001) Proceedings of the Royal Society of London B, vol. 268, p.2397
Viviparity in ichthyosaurs
“For me, the fossil is a transporting piece of evidence. It shows a female ichthyosaur that died late in pregnancy or perhaps while giving birth; the baby was entombed with its mother in the mud.” J. Rennie (2000) Scientific American, vol. 283(6), p.8
Viviparity in lizards, snakes and mammals
“In over 100 lineages of […] squamates, the oviduct has been recruited for viviparous gestation of the embryos, representing a degree of evolutionary convergence that is unparalleled in vertebrate history.” D. G. Blackburn (1998) Journal of Experimental Zoology, vol.282, p.560
Trichromatic vision in mammals
Who has not enjoyed the splash of colour in a market: gorgeous red peppers, the green of basil and what on earth are these purple vegetables over there? All thanks to trichromatic vision, another story of convergence.
Lipocalins for milk and pheromone transport
Lipocalins are proteins that bind to and transport small hydrophobic molecules such as lipids and steroids, and have been associated with biological processes such as milk production, pheromone transport and immune responses.
Birds: insights into convergence
Intriguing ecological and morphological parallels can be found among the Neoaves. Many of these forms were initially believed to be each other's closest relatives, but are now widely recognised as classic examples of convergence. Think how similar swifts and swallows are, but they are only distantly related.
Sabre-toothed cats and marsupials
Marsupials with giant fangs? Yes, not all of the extinct sabre-toothed cats were actually cats…
Woodpeckers and woodpecker-like birds and mammals
You think woodpeckers are unique? Consider the ovenbirds. Or even the curious aye-aye.
Ants: insights into convergence
Trap-jaws, silk and agriculture – just a few examples of convergence in the arguably most successful group of insects, the ants…