Beak structures in reptiles and birds
Among reptile taxa with beak structures, we find several cases of convergent evolution, for example between turtles, Uromastyx lizards, a number of herbivorous dinosaurs and the tuatara (Sphenodon) of New Zealand.

Feeding in snakes and lizards
The Turtle-headed sea snake feeds on small eggs and its feeding shows intriguing similarities to the way lizards forage, and herbivorous mammals graze and browse.

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

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

Gliding mammals
Gliding mammals rely primarily on extensive skin membranes or ‘patagia’ that stretch between fore- and hind-limbs, creating a wing-like structure.

Gliding in feathered reptiles
A number of reptile species have been discovered in the Mesozoic fossil record, bearing feathers that were apparently used to support gliding locomotion, rather than true, powered flight as we see in present day birds.

Vibrational communication in mammals
Kangaroo rats drum their foot on the ground upon encountering a snake. Why? Read on for this and many other fascinating examples of vibrational communication in mammals…

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...

Monochromacy in mammals
Underwater environments are dominated by blue light. Ironically, whales and seals cannot see blue, because they have independently lost their short-wavelength opsins.

Anointing in mammals
The strategy of anointing the body with the scent of a more dangerous animal has evolved independently several times, including in rodents, hegdehogs and tenrecs.

Suction feeding in fish, amphibians, reptiles and aquatic mammals
Probably everyone is familiar with the walrus, but did you know that it generates a vacuum in its mouth to suck clams out of their shells? And this is just one example of suction feeding, the feeding mode typically used by bony fish…

Teiid lizard dentition: convergence with other reptiles, mammals and fish
Teiids are skink-like lizards whose members show a stunning diversity of tooth types, providing rich evidence of convergence within the teiids themselves, in distantly related reptile groups and even in certain mammals and fish.

Complex tooth occlusion in notosuchid crocodiles and tritylodonts (proto-mammals)
Two unusual Early Cretaceous crocodiles provide a shining example of convergence, as their dentition parallels that observed in a group of advanced proto-mammals called tritylodonts.

Echolocation in toothed whales and ground-dwelling mammals
Given the extraordinary powers of echolocation in bats, it is not surprising that this group has received the most attention. However, they are not the only mammals to have evolved echolocation. Who invented sonar millions of years before the Navy?

Gliding mammals
Gliding mammals rely primarily on extensive skin membranes or ‘patagia’ that stretch between fore- and hind-limbs, creating a wing-like structure.

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.

Venom in mammals (and other synapsids)
Beware the venomous shrew! Yes, venomous. And convergent on some formidable lizards...

Taste in arthropods and mammals
The ability to taste is obviously an essential component in the life of any animal, both to assess the potential quality of food, its nutrient capacities and also to detect toxins or other dangers.

Baculum (penile bone) in mammals
Ouch!! Gentlemen, fancy a bone in your penis? Seems a bit risky, given it could fracture during copulation. Even our near ancestors had such a bone. It has probably evolved several times, but what is its function?

Woodpeckers and woodpecker-like birds and mammals
You think woodpeckers are unique? Consider the ovenbirds. Or even the curious aye-aye.

Penis form in mammals, turtles, birds and octopus
The specific case of a penis with a hydrostatic structure, as well as an array of collagen fibres that allows both expansion and guards against aneurysms, has evolved in a strikingly convergent fashion in mammals and turtles.

Echolocation in bats
How can bats navigate in total darkness amongst trees and branches, but still locate a tiny, fluttering insect with extraordinary acuity? All made possible through echolocation, an astonishing sensory mechanism…

Foregut fermentation in birds
A foregut-fermenting bird was long considered a paradox. But what about the hoatzin, a curious South American bird known locally as the "stinking pheasant" thanks to its smell of fresh cow manure?

Carnivorous plants
All plants are harmless? Well, not quite - at least not when you're an insect...

Agriculture in dugongs
When you think of grazing mammals, you might envisage large herds of antelopes roaming African savannahs. Did you know that there is an equivalent in the ocean, feeding on seagrass?

Vibrational communication in animals
What on earth could an elephant or treehoppers have in common with a seismometer?

Pressure sensitivity and the tactile sense (excluding the lateral line)
The star-nosed mole is famous for, well, its nose, but do you have any idea what these peculiar 'tentacles' are for? The answer is rather touching and, of course, convergent...

Lateral line system in fish and other animals
Some cavefish are completely blind, so how do they manage to navigate through their environment with astonishing ease?

Pufferfish (and inflation)
Pufferfish are some of the most extraordinary fish to have evolved, especially because of their capacity to swallow water and inflate themselves to something like a football. Not only that but some representatives can be deadly to the unwary diner...

Evolution of birds from feathered reptiles
Birds, in the sense of flying descendants of feathered reptiles (a more expansive group than the "true" birds in today's skies), evolved several times from within the theropods.

Moray eels
Eels masquerading as snakes sounds interesting, and that is before they go hunting with their friends the groupers...  

Crustacean-trapping teeth in mesosaurs and crabeater seals
The multi-lobed post-canines of Lobodon carcinophagus are a functional analogue to the long, thin cage-like teeth of Mesosaurus, as both cage and prevent the escape of small crustacean prey.

Teeth in aquatic reptiles
Aquatic reptiles tend to display one of three dentition types, well adapted to either seize and slice large vertebrate prey, pierce and gouge slippery fish, or entrap small prey such as crustaceans.

Dental batteries in ceratopsians, hadrosaurs and elephants
The dental batteries or 'pavements' of ceratopsians and hadrosaurs evolved independently, and yet the dentition of several more distantly related animals also converges on their highly adapted tooth form.

Reptile dentition: convergence on complex occlusion
Some reptiles have transverse chisel-like teeth for slicing, and others have teeth bearing projections ('cusps') that interlock and slice or grind tough food. In each case evolutionary parallels are clear both within and outside the reptiles.

Beak structures in reptiles and birds
Among reptile taxa with beak structures, we find several cases of convergent evolution, for example between turtles, Uromastyx lizards, a number of herbivorous dinosaurs and the tuatara (Sphenodon) of New Zealand.

Venom and venom fangs in snakes, lizards and synapsids
Although the evolution of snake fangs itself provides us with a window on convergence, the presence of fang-like teeth in lizards, therapsids and mammals provides an even broader and more remarkable perspective.

Feeding in snakes and lizards
The Turtle-headed sea snake feeds on small eggs and its feeding shows intriguing similarities to the way lizards forage, and herbivorous mammals graze and browse.

Independent eye movement in fish, chameleons and frogmouths
One of the most surprising convergences amongst animals is that seen between a small fish that lives in coral sands, known as the sandlance, and the lizards known as chameleons.

Bats: Insights into convergence
Bats show a fascinating array of convergences, from echolocation to flight to nectar feeding. Vampire bats can even detect infrared radiation, while others might be able to see into the ultraviolet end of the spectrum.

Thanatosis (feigning death) in spiders and insects
Beetles that "play possum"? A rather interesting example of convergence…

Durophagy (hard prey-eating) in fish
Plenty of animals have an extraordinary capacity to crush hard prey and this has evolved independently many times in the vertebrates. If you suspect it is a durophage, watch your fingers!

Gliding lizards, frogs and ants
Tree-dwelling (‘arboreal’) ants capable of controlled gliding do so when dislodged or threatened by predation. Gliding species include members of three disparate families: Myrmicinae, Pseudomyrmecinae and Formicinae.

Gliding in feathered reptiles
A number of reptile species have been discovered in the Mesozoic fossil record, bearing feathers that were apparently used to support gliding locomotion, rather than true, powered flight as we see in present day birds.

Gliding in Draco lizards and tree snakes
“The agamid lizard genus Draco (consisting of the so-called ‘flying dragons’) exhibits an array of morphological traits associated with gliding.” – A.P. Russell & L.D. Dijkstra (2001) Journal of the Zoological Society of London, vol. 253, page 457

Gliding reptiles
In the reptiles, different forms of skin membrane (called ‘patagia’) and in some extinct species, primitive feathers, have evolved convergently as adaptations for gliding.

Ecological adaptations in Moloch and Phrynosoma lizards
Lizards of the genera Phrynosoma and Moloch have been considered a classic example of convergent evolution J. J. Meyers & A. Herrel (2005) The Journal of Experimental Biology, vol. 208, p. 114

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

Olfaction: insights into convergence
Although olfaction is very widespread, there is abundant evidence for repeated convergence of key features, strongly suggesting that there really is an optimal solution to detecting smells.

Infrared detection in snakes
Warm-blooded rodents watch out! There are heat-sensing predators on the prowl...

Infrared detection in animals
Some snakes are famous for 'seeing' infrared, but did you know that their heat-sensing abilities are rivalled by some beetles that can detect forest fires over considerable distances?

Loss of olfactory capacity in primates and cetaceans
It is widely thought that reduced olfactory capacity in apes is linked to the development of acute vision, especially trichromacy.

Hearts in cephalopods and vertebrates
There is a striking convergence between the aorta of the cephalopod and vertebrate heart, notably in its structure and the employment of elastic proteins.

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.

Wire plants, moas and elephant birds
Madagascar and New Zealand were once home to giant herbivorous birds. And the plants have not forgotten...    

Adhesive pads: from geckos to spiders
In terms of adhesive pads we find they have a remarkably wide distribution evolving in at least four distinct groups, including members of the reptiles, amphibians, arthropods and mammals, with tentative parallels in sea urchins.

Lysozyme
Lysozymes are common antibacterial enzymes that protect our eyes and nose from infection, but some animals have recruited them for a rather different purpose...

Intelligence and cognition in birds
House sparrows are known to gain access to shopping malls by flying in front of sensors that operate sliding doors, whilst herons have been shown to be adept fishers using baits and lures.

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.

Gut fermentation in herbivorous animals
Ever tried eating a newspaper? Don't. Plant cell walls contain cellulose, which is notoriously difficult to digest. Considering that all vertebrates lack the enzymes to attack this polysaccharide, how do so many of them manage to survive on a plant diet?

Carbonic anhydrase in vertebrates, plants, algae and bacteria
Carbonic anhydrase is extremely convergent and may have evolved as many as six times. The most familiar variants are α, β and γ carbonic anhydrases.

Tool use in birds
What animals can drop stones into a water-filled tube to bring floating food within reach or bend wire to form a hook? Obviously chimpanzees? No, New Caledonian crows have evolved sophisticated tool use too.

Sabre-toothed cats and marsupials
Marsupials with giant fangs? Yes, not all of the extinct sabre-toothed cats were actually cats…

Sap feeding and honey-dew production in insects
Interestingly, it has now been shown that the saliva of the aphids has an analogue to the anti-coagulant properties of blood suckers, subverting the wound repair mechanism of the plant.

Electric fish: insights into convergence
Ever seen an electric eel in an aquarium? Don’t dare putting your hand in the tank...

Dolphin communication, cognition and sociality
Dolphins are one of the most intriguing sources of evolutionary convergence, having cognitive abilities that seem to find many parallels in the great apes, and rather remarkably even extend to tool use.

Sleep in animals
Suffering from insomnia? Fruit flies do as well...

Agriculture: from ants to dugongs
Human farmers tending their fields are a familiar sight. But don't forget about those fungus-farming termites or the fish with a garden of algae…

Zinc in teeth
On land, we find the employment of zinc to reinforce feeding structures in the fangs of spiders, and also in a variety of insect groups.

Beetles: insights into convergence
The beetles are probably the most diverse animal group on earth, so it is not at all surprising that they provide many fascinating insights into convergence.

Swimming and thermoregulation in sharks and tuna
Thunniform swimming depends on a large, lunate tail that is joined to the rest of the body via a narrow peduncle. Whilst the tail flicks backwards and forwards, so propelling the animal, the rest of the body hardly moves sideways.

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…

Crustaceans: insights into convergence
Whilst predominantly marine, quite a number of crustaceans have invaded freshwater habitats and even more interestingly a few demonstrate terrestrialization, effectively freeing themselves from their aquatic ancestry.

“Colour vision” in Firefly squid
The Japanese firefly squid (Watasenia scintillans), which inhabits the deep ocean, has three visual pigments located in different parts of the retina that are likely to allow colour discrimination as they each have distinct spectral sensitivities.

Frogs with fangs
Teeth have clearly evolved a number of times, and one of the more interesting curiosities is found in the amphibians, notably in the frogs where several groups have independently evolved fangs.

Electroreception in fish, amphibians and monotremes
From an evolutionary point of view, electroreception is particularly intriguing as a sense modality that has been repeatedly lost and reinvented again.

Burrowing: from worms to vertebrates
Quite a few adaptations are useful for burrowing into the soil. So it is not exactly surprising that they have evolved several times...

Octopus arm function
If you want to see a truly remarkable example of convergence, then present an octopus with a piece of food and have a high-speed camera ready…

Octopus and other cephalopods: convergence with vertebrates
What could be more different from us than the alien-like octopus? Hold on. Look it in the eye and think again.