Evolution of the Bony Projection on Ailurus fulgens
Melanie Brown
Dixie State University
Author Note:
This paper was prepared for Evolution 3010, class instructed by Dr. Curtis Walker
Throughout the evolution of the hand, most commonly found in primates, advantages of a thumb have led to the improvement of activities such as gripping and squeezing. Over time, few species developed full capabilities and usage of the thumb. Some species developed slightly while others did not develop it at all. For the species Ailurus fulgens, also known as the Red Panda, a “remnant” of a thumb remains. This “thumb,” better categorized as a pseudo-thumb, helps aid the panda in the processes of eating and climbing.
The ancestry of the Ailurus …show more content…
The sesamoid bone of this species resembles that of a red panda which supports taxonomic relationship placing it in the Ailuridae family, the same as the red panda. The Simocyon batelleri fossils suggest that traits such as tree living environments and hyper carnivore diets were present (Glatston, 2010). This trait which is also included in giant pandas, noting they are a different species than that of the red panda, challenge the hypothesis whether the red panda and giant panda are actually related. This is because the presence of the pseudo-thumb found in the Simocyon, is not the only indicator of common ancestry between the two species, but structure of the teeth come into play as well. Fossil evidence shows that the diet of a Simocyon would have a more general carnivorous diet instead of an herbivorous diet that both red and giant pandas have. The question is then, if Simocyon did not have an herbivorous diet, what was the function of the sesamoid bone? Further evidence suggests that this red panda relative had elongated transverse processes that are used in the aid of flexing the back and the legs, a common feature found in small carnivores for sprinting and climbing. It is possible that the origins of the pseudo-thumb present in the red panda may have evolved for a less active lifestyle than that of the Simocyon and now is used primarily for the function of leaf separation. But again, the unique trait found in this species was the radial sesamoid bone which is the only known species to have a developed pseudo-thumb other than the pandas, a clear example of convergent
Melanie Brown
Dixie State University
Author Note:
This paper was prepared for Evolution 3010, class instructed by Dr. Curtis Walker
Throughout the evolution of the hand, most commonly found in primates, advantages of a thumb have led to the improvement of activities such as gripping and squeezing. Over time, few species developed full capabilities and usage of the thumb. Some species developed slightly while others did not develop it at all. For the species Ailurus fulgens, also known as the Red Panda, a “remnant” of a thumb remains. This “thumb,” better categorized as a pseudo-thumb, helps aid the panda in the processes of eating and climbing.
The ancestry of the Ailurus …show more content…
The sesamoid bone of this species resembles that of a red panda which supports taxonomic relationship placing it in the Ailuridae family, the same as the red panda. The Simocyon batelleri fossils suggest that traits such as tree living environments and hyper carnivore diets were present (Glatston, 2010). This trait which is also included in giant pandas, noting they are a different species than that of the red panda, challenge the hypothesis whether the red panda and giant panda are actually related. This is because the presence of the pseudo-thumb found in the Simocyon, is not the only indicator of common ancestry between the two species, but structure of the teeth come into play as well. Fossil evidence shows that the diet of a Simocyon would have a more general carnivorous diet instead of an herbivorous diet that both red and giant pandas have. The question is then, if Simocyon did not have an herbivorous diet, what was the function of the sesamoid bone? Further evidence suggests that this red panda relative had elongated transverse processes that are used in the aid of flexing the back and the legs, a common feature found in small carnivores for sprinting and climbing. It is possible that the origins of the pseudo-thumb present in the red panda may have evolved for a less active lifestyle than that of the Simocyon and now is used primarily for the function of leaf separation. But again, the unique trait found in this species was the radial sesamoid bone which is the only known species to have a developed pseudo-thumb other than the pandas, a clear example of convergent