I was asked by Chewbacca whether the 'proper' Genus name for Red-foots is Geochelone or Chelonoidis. This is a summary of the research I have done on this:
The scientific names of a lot of species are in a turmoil right now as DNA and other research is changing how we look at what is related to what. In theory, any two members of the same species can freely interbreed. That is the main issue- what things are related enough to breed.
When Scientific names were just starting, Karl Linneaus was trying to group plants and animals in logical ways. He and most people for a century afterwards based this mostly on looks, behavior, and location. In 1788, ALL tortoises were some variation of the Genus Testudo. The South American tortoises with the dark shells and light patterns were called 'Testudo denticulata' for the toothed edge on the back of the shell.
In 1824, the South American explorer and naturalist J. B. von Spix decided that there were two similar tortoises in South America and called the 'smooth edged' one Testudo carbonaria. Because of how slowly information moved at this time, it was not widely accepted, and the differences between the two were poorly defined. Many museum specimens were mis-labeled, etc.
In 1826, Leopold Fitzinger did a lot of muddying the waters. He created the genus names of Geochelone and Chelonoidis, he called the Red-foot G. carbonaria and the Yellow C. denticulata. To make matters worse, he labeled something as G. tabulata, a name that pops up from time to time.
1833- Wagler introduces the name Testudo boiei to both species, even though he is credited with figuring out how to tell the difference between the two- and the who idea of two species falls into disuse until the late 1950's.
Confused yet? Its a mess, isn't it? it goes on for another hundred years like this- a hodge-podge of names and variations on names.
In the 1950's, people like Loveridge and Ernest Williams are trying to clear things up and settle on Geochelone carbonaria and G. denticulata Not everyone buys this at the time, and there is still some bickering between names, relationships, etc. There is an on-going war between 'lumpers and splitters'- people who try to group as many animals together as possible, and those who try to make each variant a species. Fight and bicker for another 50 years.
In 1980 to present, a few things happen. We start to look at animal DNA and more carefully at skeletons- if two animals have almost the same small skeletal structures, like the details of bones around the eye and ear, they are usually closely related. They started to think that the South American tortoises are not closely enough related to the African tortoises to share the name Geochelone. Another change is that scientists have worked harder at using the 'right' name by the official naming rules- one of the rules is that the oldest specific and accurate names trump newer ones. The oldest name for these tortoises that cannot be applied to any other is 'Chelonoidis' (which roughly means 'of the turtle', while Geochelone means 'earth turtle').
A Frenchman named Roger Bour started this in 1980 by studying the skulls of various tortoises. For about 20 years, it was mostly just used in France (even with modern communications, ideas still sometimes move slowly), but it has been used more and more widely lately.
Currently, as I understand it, the most "accurate" name is Chelonoidis, but Geochelone is still widely used, and is the name most often seen in print in many publications.
So- I think they are Chelonoidis carbonaria, but will not argue with anyone using Geochelone. You will also often see a compromise in which one or the other name is in parenthesis, like Geochelone (Chelonoidis) carbonaria.
The scientific names of a lot of species are in a turmoil right now as DNA and other research is changing how we look at what is related to what. In theory, any two members of the same species can freely interbreed. That is the main issue- what things are related enough to breed.
When Scientific names were just starting, Karl Linneaus was trying to group plants and animals in logical ways. He and most people for a century afterwards based this mostly on looks, behavior, and location. In 1788, ALL tortoises were some variation of the Genus Testudo. The South American tortoises with the dark shells and light patterns were called 'Testudo denticulata' for the toothed edge on the back of the shell.
In 1824, the South American explorer and naturalist J. B. von Spix decided that there were two similar tortoises in South America and called the 'smooth edged' one Testudo carbonaria. Because of how slowly information moved at this time, it was not widely accepted, and the differences between the two were poorly defined. Many museum specimens were mis-labeled, etc.
In 1826, Leopold Fitzinger did a lot of muddying the waters. He created the genus names of Geochelone and Chelonoidis, he called the Red-foot G. carbonaria and the Yellow C. denticulata. To make matters worse, he labeled something as G. tabulata, a name that pops up from time to time.
1833- Wagler introduces the name Testudo boiei to both species, even though he is credited with figuring out how to tell the difference between the two- and the who idea of two species falls into disuse until the late 1950's.
Confused yet? Its a mess, isn't it? it goes on for another hundred years like this- a hodge-podge of names and variations on names.
In the 1950's, people like Loveridge and Ernest Williams are trying to clear things up and settle on Geochelone carbonaria and G. denticulata Not everyone buys this at the time, and there is still some bickering between names, relationships, etc. There is an on-going war between 'lumpers and splitters'- people who try to group as many animals together as possible, and those who try to make each variant a species. Fight and bicker for another 50 years.
In 1980 to present, a few things happen. We start to look at animal DNA and more carefully at skeletons- if two animals have almost the same small skeletal structures, like the details of bones around the eye and ear, they are usually closely related. They started to think that the South American tortoises are not closely enough related to the African tortoises to share the name Geochelone. Another change is that scientists have worked harder at using the 'right' name by the official naming rules- one of the rules is that the oldest specific and accurate names trump newer ones. The oldest name for these tortoises that cannot be applied to any other is 'Chelonoidis' (which roughly means 'of the turtle', while Geochelone means 'earth turtle').
A Frenchman named Roger Bour started this in 1980 by studying the skulls of various tortoises. For about 20 years, it was mostly just used in France (even with modern communications, ideas still sometimes move slowly), but it has been used more and more widely lately.
Currently, as I understand it, the most "accurate" name is Chelonoidis, but Geochelone is still widely used, and is the name most often seen in print in many publications.
So- I think they are Chelonoidis carbonaria, but will not argue with anyone using Geochelone. You will also often see a compromise in which one or the other name is in parenthesis, like Geochelone (Chelonoidis) carbonaria.
