Who has the most horns?

Who has the most horns?

Internationaler Chamäleontag

Many chameleons have horns or other rostral appendages. But who has the most? The regular one is the four-horned chameleon, Trioceros quadricornis. It occurs in Cameroon and Nigeria. The males of this species in particular usually have four real horns on their nose. The subspecies Trioceros quadricornis gracilior can even occasionally have up to six horns – but this horn record is not common. Incidentally, even the females of this species can be horned – this is not the case with many other species.

Incidentally, a distinction is made between true horns and false horns in chameleons. Chameleons with true horns have a bony process on their nose that is covered by a thin layer of keratin. This keratin layer develops from a single scale. These true horns are mainly found in the genus Trioceros. In contrast, false horns also have a bony base, but are covered with normal, scaly skin. False horns are found in many Malagasy chameleons. Finally, there are dermal horns, which consist only of skin. They are soft, flexible and have no bone underneath. These horns are also mainly found in Malagasy chameleons.

#show your colours #internationalchameleonday #chameleonday #chameleondayMay9 #agchamaeleons

Photo: Jackson’s chameleon, Trioceros jacksonii, also has real horns; Creative Commons Attribution-Share Alike 3.0 Unported, fotografiert von Benjamint444

Comparison of pelvic girdles in chameleons

Comparison of pelvic girdles in chameleons


The anatomy of chameleons is strongly adapted to their way of life. Tree-dwellers differ in many aspects from ground-dwellers. The pelvic girdle has been little studied anatomically in chameleons so far – a publication from the USA now deals with it in more detail.

For the study, the pelvic girdles of 22 chameleons were isolated from existing microcomputer tomography scans and displayed in 3D. These were measured to 16 different lengths and angles using software. Archaius tigris, Bradypodion damaranum, Calumma gallus, Calumma parsonii parsonii, Chamaeleo zeylanicus, Furcifer balteatus, Kinyongia matschiei, Kinyongia tavetana, Nadzikambia mlanjense and Trioceros quadricornis gracilior were assigned to tree dwellers. Brookesia brygooi, Chamaeleo namaquensis, Palleon nasus nasus, Rhampholeon temporalis and Rieppeleon brachyurus were attributed to ground-dwelling species. The species Bradypodion occidentale, Brookesia ebenaui, Chamaeleo anchietae, Furcifer campani, Rhampholeon spinosus, Rieppeleon kerstenii kerstenii and Trioceros goetzei goetzei were classified as semiarboreal. Mainly males were examined.

As expected, the evaluation showed that tree-dwelling chameleons had narrower, shorter girdles than ground-dwelling ones. The narrower pelvic girdle makes it easier to hide behind branches and flatten the body to the maximum. It also ensures that the body’s centre of gravity is closer to the branch and thus increases stability when climbing. Ground-dwelling chameleons, on the other hand, had larger and wider pelvic girdles. These allow them to step more quickly and provide greater stability when walking on ground surfaces.

How phylogeny and arboreality affect pelvic girdle anatomy of chameleons
Dakota J. John
Honors Thesis 299, University of South Dakota, 2023
DOI: none