Post by Felis Rex on May 11, 2013 0:38:31 GMT -5
With all this dragon introduction hypothesis, and dragon vs. mainland carnivore debates, I thought maybe we should explore the nature of these animals, and others in the same boat, in their isolated disposition. First off....
Both reptiles and birds, reach phenomenal sizes (some of the largest Holocene specimens,) along with certain mammals and invertebrates.
Some examples..
Mammals
Soricomorphs
Corsican giant shrew (extinct)
Balearic giant shrew (extinct)
Erinaceomorphs
Deinogalerix (extinct)
Rodents
Flores giant rat
Tenerife giant rat and Gran Canaria giant rat (both extinct)
Giant hutias of the West Indies (extinct)
Majorcan giant dormouse and Minorcan giant dormouse (both extinct)
Formentera black-tailed garden dormouse, descendant of garden dormice introduced from the continent by Neolithic humans
Lagomorphs
Minorcan giant lagomorph (extinct)
Different Prolagus Mediterranean species, including the extinct Sardinian pika and P. imperialis from Gargano Island
Primates
Giant lemurs Archaeoindris, Palaeopropithecus and Megaladapis of Madagascar (all extinct)
Birds
Ratites
The elephant bird, among the largest birds ever, formerly living on Madagascar (extinct).
The extinct moa of New Zealand.
Waterfowl
Moa-nalos, extinct giant ducks from Hawaii.
The extinct giant Siculo-Maltese swan, Cygnus falconeri.
Wildfowl
Sylviornis neocaledoniae a huge extinct megapode-like bird from New Caledonia
Some extinct Polynesian megapodes.
Rails
The takahēs from New Zealand and other Porphyrio as well as many Gallirallus species from Melanesia and Polynesia and a few other rallids.
Seabirds
The extinct spectacled cormorant from Bering Island.
Pigeons
Dodo and Rodrigues solitaire, both extinct, from the Mascarenes
The extinct flightless Viti Levu giant pigeon.
Birds of prey
Haast's eagle and Eyles' harrier of New Zealand; the titan-hawk Titanohierax and giant-hawk Gigantohierax from the Caribbean; the giant buteonine hawk Buteogallus borrasi of Cuba (all now extinct).[3]
Parrots
The extinct broad-billed parrot from Mauritius, an undescribed huge extinct parrot from Easter Island, and the critically endangered kakapo of New Zealand.
The largest tortoises in the world are found on the Seychelles and Galápagos Islands (example of the latter shown).
Owls
The Cuban giant flightless owl Ornimegalonyx, the possibly flightless Cretan owl, and several Tyto barn owls from the Mediterranean (Tyto robusta, Tyto gigantea), Caribbean (Tyto pollens) and Melanesia (all of them extinct).
Storks
The Flores flightless stork, Leptoptilos robustus, a very large extinct stork from Flores.
Reptiles
Turtles
Giant tortoises in the Galápagos Islands, Seychelles, and formerly the Mascarenes are often considered examples of island gigantism. However, during the Pleistocene, comparably sized or larger tortoises were present in Australia (Meiolania), southern Asia (Colossochelys atlas), Madagascar (Dipsochelys) and North and South America, as well as on a number of other, more accessible islands. In the late Pliocene they were also present in Africa. The present situation of large tortoises being only found on remote islands may reflect that these islands were discovered by humans fairly recently and have not been heavily populated, making their tortoises less subject to overexploitation.
The Komodo dragon of Flores and nearby islands is the largest living lizard.
Lizards
The Komodo dragon and a similar (extinct) giant monitor lizard from Timor, examples of giant insular carnivores. Since islands tend to offer limited food and territory, their mammalian carnivores (if present) are usually smaller than continental ones. These cases involve ectothermic carnivores on islands too small to support much mammalian competition. However, these lizards are not as large as their extinct Australian relative Megalania, and it has been proposed based on fossil evidence that the ancestors of these varanids first evolved their large size in Australia and then dispersed to Indonesia. If this is true, rather than being insular giants they would be viewed as examples of phyletic gigantism. Nevertheless, given that Australia is sometimes viewed as the world's largest island, the former view may not be entirely invalid.
The Angel Island chuckwalla (Sauromalus hispidus) and the San Esteban chuckwalla (Sauromalus varius) of islands off Baja California
The extinct giant (1.5 m long) iguana Lapitiguana from Fiji.
Leiolopisma mauritiana and Macroscincus coctei, two extinct skinks from Mauritius and Cape Verde, the Solomon Islands skink and the rare New Caledonian skink Phoboscincus bocourti
The extinct Rodrigues giant day gecko and New Zealand giant gecko, and the extant New Caledonian giant gecko
Four extant and one extinct species of lacertid lizard of the genus Gallotia in the Canary Islands
Snakes
Tiger snake populations on Mount Chappell Island (Tasmania) and Williams Island, Hopkins Island and islands of the Nuyts Archipelago (South Australia). On these islands the available prey is restricted to larger sizes than commonly taken by mainland snakes; restricted seasonal availability of prey also appears to contribute to gigantism.
Arthropods
Conant's giant Nihoa tree cricket
Giant pill-millipedes of Madagascar
Giant wetas of New Zealand
Saint Helena earwig
Taveuni and giant Fijian long-horned beetles of Fiji
On the opposite end of the spectrum we have Island Dwarfism. This is perhaps most obvious among ungulates and other large mammals.
A general rundown...
Some examples,
Carnivora
Bali tiger †
Channel Island fox in California, United States, and the enigmatic, nearly extinct Cozumel fox
Cozumel raccoon
Honshū wolf † in Japan
Sardinian dhole †
Zanzibar leopard, possibly extinct
Ungulates
Key deer of the Florida Keys
Extinct red deer populations in Jersey
Philippine sambar
Candiacervus ropalophorus †, Crete
Cervus astylodon †, Ryukyu Islands of Japan
Hoplitomeryx †, the Gargano promontory (the former Gargano Island) of South Italy
Philippine water buffalo, tamaraw, anoa, the extinct Bubalus cebuensis † and other dwarf bovids from Southeast Asia
The strange, tiny Balearic Islands cave goat (Myotragus balearicus) † in Majorca and Minorca and its close relative Nesogoral †, from Sardinia which became extinct after human settlement
Several extinct species of dwarf hippopotamus from the Pleistocene of Mediterranean islands (such as Hippopotamus minor) † and Madagascar
Birds
King Island emu and Kangaroo Island emu, both extinct
Lizards
Brookesia micra, a less than 3.0 cm long chameleon from the islet of Nosy Hara off the northern tip of Madagascar, one of the "smallest amniote vertebrates in the world"
Snakes
Tiger snakes of Roxby Island, South Australia
Reticulated pythons of Tanahjampea island (P. r. jampeanus), between Sulawesi and Flores in Indonesia.
What wiki calls "Famous Examples"
Dinosaurs, including the recently validated Europasaurus, on Mesozoic islands such as Haţeg Island, Romania. Other dwarf dinosaurs, mainly from Haţeg Island, include Magyarosaurus, Rhabdodon, Balaur bondoc and Telmatosaurus. Also, the dwarf nodosaurid Struthiosaurus from Europe.
Dwarf ground sloths in the recent natural history of Cuba, Hispaniola, and Puerto Rico. (There is also a living dwarf tree sloth on Isla Escudo de Veraguas.)
The Channel Islands mammoth which lived on the prehistoric island of Santa Rosae in the California Channel Islands, and the small woolly mammoths of Saint Paul Island off Alaska, and Wrangel Island north of Siberia.
Dwarf elephants or mammoths in the recent natural history of Malta, Crete, Cyprus, Sardinia, Sicily and several of the Cyclades and Dodecanese islands.
Dwarf stegodonts (elephant relatives) from the recent natural history of the Philippines, Flores, Sulawesi, Sumba and Timor.
A recently confirmed separate species of hominid called Homo floresiensis, from fossils found on Flores Island in Indonesia.
Small-bodied humans from Palau, Micronesia, similar in size to the Flores hominins (disputed).
Island gigantism or insular giantism is a biological phenomenon in which the size of animals isolated on an island increases dramatically in comparison to their mainland relatives. Island gigantism is one aspect of the more general "island rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies. With the arrival of humans and associated predators (dogs, cats, rats, pigs), many giant island endemics have become extinct.
Both reptiles and birds, reach phenomenal sizes (some of the largest Holocene specimens,) along with certain mammals and invertebrates.
Some examples..
Mammals
Soricomorphs
Corsican giant shrew (extinct)
Balearic giant shrew (extinct)
Erinaceomorphs
Deinogalerix (extinct)
Rodents
Flores giant rat
Tenerife giant rat and Gran Canaria giant rat (both extinct)
Giant hutias of the West Indies (extinct)
Majorcan giant dormouse and Minorcan giant dormouse (both extinct)
Formentera black-tailed garden dormouse, descendant of garden dormice introduced from the continent by Neolithic humans
Lagomorphs
Minorcan giant lagomorph (extinct)
Different Prolagus Mediterranean species, including the extinct Sardinian pika and P. imperialis from Gargano Island
Primates
Giant lemurs Archaeoindris, Palaeopropithecus and Megaladapis of Madagascar (all extinct)
Birds
Ratites
The elephant bird, among the largest birds ever, formerly living on Madagascar (extinct).
The extinct moa of New Zealand.
Waterfowl
Moa-nalos, extinct giant ducks from Hawaii.
The extinct giant Siculo-Maltese swan, Cygnus falconeri.
Wildfowl
Sylviornis neocaledoniae a huge extinct megapode-like bird from New Caledonia
Some extinct Polynesian megapodes.
Rails
The takahēs from New Zealand and other Porphyrio as well as many Gallirallus species from Melanesia and Polynesia and a few other rallids.
Seabirds
The extinct spectacled cormorant from Bering Island.
Pigeons
Dodo and Rodrigues solitaire, both extinct, from the Mascarenes
The extinct flightless Viti Levu giant pigeon.
Birds of prey
Haast's eagle and Eyles' harrier of New Zealand; the titan-hawk Titanohierax and giant-hawk Gigantohierax from the Caribbean; the giant buteonine hawk Buteogallus borrasi of Cuba (all now extinct).[3]
Parrots
The extinct broad-billed parrot from Mauritius, an undescribed huge extinct parrot from Easter Island, and the critically endangered kakapo of New Zealand.
The largest tortoises in the world are found on the Seychelles and Galápagos Islands (example of the latter shown).
Owls
The Cuban giant flightless owl Ornimegalonyx, the possibly flightless Cretan owl, and several Tyto barn owls from the Mediterranean (Tyto robusta, Tyto gigantea), Caribbean (Tyto pollens) and Melanesia (all of them extinct).
Storks
The Flores flightless stork, Leptoptilos robustus, a very large extinct stork from Flores.
Reptiles
Turtles
Giant tortoises in the Galápagos Islands, Seychelles, and formerly the Mascarenes are often considered examples of island gigantism. However, during the Pleistocene, comparably sized or larger tortoises were present in Australia (Meiolania), southern Asia (Colossochelys atlas), Madagascar (Dipsochelys) and North and South America, as well as on a number of other, more accessible islands. In the late Pliocene they were also present in Africa. The present situation of large tortoises being only found on remote islands may reflect that these islands were discovered by humans fairly recently and have not been heavily populated, making their tortoises less subject to overexploitation.
The Komodo dragon of Flores and nearby islands is the largest living lizard.
Lizards
The Komodo dragon and a similar (extinct) giant monitor lizard from Timor, examples of giant insular carnivores. Since islands tend to offer limited food and territory, their mammalian carnivores (if present) are usually smaller than continental ones. These cases involve ectothermic carnivores on islands too small to support much mammalian competition. However, these lizards are not as large as their extinct Australian relative Megalania, and it has been proposed based on fossil evidence that the ancestors of these varanids first evolved their large size in Australia and then dispersed to Indonesia. If this is true, rather than being insular giants they would be viewed as examples of phyletic gigantism. Nevertheless, given that Australia is sometimes viewed as the world's largest island, the former view may not be entirely invalid.
The Angel Island chuckwalla (Sauromalus hispidus) and the San Esteban chuckwalla (Sauromalus varius) of islands off Baja California
The extinct giant (1.5 m long) iguana Lapitiguana from Fiji.
Leiolopisma mauritiana and Macroscincus coctei, two extinct skinks from Mauritius and Cape Verde, the Solomon Islands skink and the rare New Caledonian skink Phoboscincus bocourti
The extinct Rodrigues giant day gecko and New Zealand giant gecko, and the extant New Caledonian giant gecko
Four extant and one extinct species of lacertid lizard of the genus Gallotia in the Canary Islands
Snakes
Tiger snake populations on Mount Chappell Island (Tasmania) and Williams Island, Hopkins Island and islands of the Nuyts Archipelago (South Australia). On these islands the available prey is restricted to larger sizes than commonly taken by mainland snakes; restricted seasonal availability of prey also appears to contribute to gigantism.
Arthropods
Conant's giant Nihoa tree cricket
Giant pill-millipedes of Madagascar
Giant wetas of New Zealand
Saint Helena earwig
Taveuni and giant Fijian long-horned beetles of Fiji
On the opposite end of the spectrum we have Island Dwarfism. This is perhaps most obvious among ungulates and other large mammals.
A general rundown...
Insular dwarfism, a form of phyletic dwarfism, is the process and condition of the reduction in size of large animals over a number of generations when their population's range is limited to a small environment, primarily islands. This natural process is distinct from the intentional creation of dwarf breeds, called dwarfing. This process has occurred many times throughout evolutionary history, with examples including dinosaurs, like Europasaurus, and modern animals such as elephants and their relatives. This process, and other "island genetics" artifacts, can occur not only on traditional islands, but also in other situations where an ecosystem is isolated from external resources and breeding. This can include caves, desert oases, isolated valleys and isolated mountains ("sky islands"). Insular dwarfism is one aspect of the more general "island rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies.
Some examples,
Carnivora
Bali tiger †
Channel Island fox in California, United States, and the enigmatic, nearly extinct Cozumel fox
Cozumel raccoon
Honshū wolf † in Japan
Sardinian dhole †
Zanzibar leopard, possibly extinct
Ungulates
Key deer of the Florida Keys
Extinct red deer populations in Jersey
Philippine sambar
Candiacervus ropalophorus †, Crete
Cervus astylodon †, Ryukyu Islands of Japan
Hoplitomeryx †, the Gargano promontory (the former Gargano Island) of South Italy
Philippine water buffalo, tamaraw, anoa, the extinct Bubalus cebuensis † and other dwarf bovids from Southeast Asia
The strange, tiny Balearic Islands cave goat (Myotragus balearicus) † in Majorca and Minorca and its close relative Nesogoral †, from Sardinia which became extinct after human settlement
Several extinct species of dwarf hippopotamus from the Pleistocene of Mediterranean islands (such as Hippopotamus minor) † and Madagascar
Birds
King Island emu and Kangaroo Island emu, both extinct
Lizards
Brookesia micra, a less than 3.0 cm long chameleon from the islet of Nosy Hara off the northern tip of Madagascar, one of the "smallest amniote vertebrates in the world"
Snakes
Tiger snakes of Roxby Island, South Australia
Reticulated pythons of Tanahjampea island (P. r. jampeanus), between Sulawesi and Flores in Indonesia.
What wiki calls "Famous Examples"
Dinosaurs, including the recently validated Europasaurus, on Mesozoic islands such as Haţeg Island, Romania. Other dwarf dinosaurs, mainly from Haţeg Island, include Magyarosaurus, Rhabdodon, Balaur bondoc and Telmatosaurus. Also, the dwarf nodosaurid Struthiosaurus from Europe.
Dwarf ground sloths in the recent natural history of Cuba, Hispaniola, and Puerto Rico. (There is also a living dwarf tree sloth on Isla Escudo de Veraguas.)
The Channel Islands mammoth which lived on the prehistoric island of Santa Rosae in the California Channel Islands, and the small woolly mammoths of Saint Paul Island off Alaska, and Wrangel Island north of Siberia.
Dwarf elephants or mammoths in the recent natural history of Malta, Crete, Cyprus, Sardinia, Sicily and several of the Cyclades and Dodecanese islands.
Dwarf stegodonts (elephant relatives) from the recent natural history of the Philippines, Flores, Sulawesi, Sumba and Timor.
A recently confirmed separate species of hominid called Homo floresiensis, from fossils found on Flores Island in Indonesia.
Small-bodied humans from Palau, Micronesia, similar in size to the Flores hominins (disputed).
