Red side-necked turtle explained

The red side-necked turtle (Rhinemys rufipes), red turtle, red-footed sideneck turtle, William's toadhead turtle, or red-footed Amazon side-necked turtle^[1] is a monotypic species of turtle in the family Chelidae. It is found in Brazil, Colombia, and possibly Peru.^[1] This species is dimorphic in size meaning the sexes show different characteristics.^[2] One study found that the largest female out of a group of 24 was 256 mm in carapace length. Out of that same group, the largest male was only 199 mm in carapace length. A study focused on determining how these turtles acquire their sex discovered that it is not environmentally determined rather, it is a genetic sex determination.^[3]

Notes and References

1. http://reptile-database.reptarium.cz/species?genus=Rhinemys&species=rufipes&search_param=%28%28genus%3D%27Rhinemys%27%2Cexact%29%29 Rhinemys rufipes
2. Viana PF, Feldberg E, Cioffi MB, de Carvalho VT, Menezes S, Vogt RC, Liehr T, Ezaz T . 6 . The Amazonian Red Side-Necked Turtle Rhinemys rufipes (Spix, 1824) (Testudines, Chelidae) Has a GSD Sex-Determining Mechanism with an Ancient XY Sex Microchromosome System . Cells . 9 . 9 . 2088 . September 2020 . 32932633 . 7563702 . 10.3390/cells9092088 . free .
3. Viana, P. F., Feldberg, E., Cioffi, M. B., de Carvalho, V. T., Menezes, S., Vogt, R. C., Liehr, T., & Ezaz, T. (2020). The Amazonian Red Side-Necked Turtle Rhinemys rufipes (Spix, 1824) (Testudines, Chelidae) Has a GSD Sex-Determining Mechanism with an Ancient XY Sex Microchromosome System. Cells (Basel, Switzerland), 9(9), 1–.