A new species has been discovered. The animal is a vertebrate, approximately 18-24 inches in length. Members of this species are covered in scales and are known to lay shelled eggs. Dissection has also shown that this animal possesses a four-chambered heart. Its skeleton is shown below, but the skull has been omitted. An image of the skeleton is shown below. A sample of the skull could not be obtained, but some characteristics of the skeletal structure of the head were observed: the skull lacks a sclerotic ring (bony ring which supports the eyeball), but possesses a secondary bony palate.
In order to classify the unknown species, let us first dissect the observed characteristic until we can come up with a good taxonomical identification.
Since it is a vertebrate, it is classified under
Many animals are egg-laying and scaly so we will consider these characteristics later.
Animals that have four chambered heart are bird and mammals. We can disregard the other animal classes. This leaves us to two options:
Class: Aves or Mammalia
Sclerotic ring is present in many vertebrates except mammals and some species of crocodiles. This characteristic can disregard birds as class and therefore the unknown animal is a mammal.
Secondary bony palate is a structure that divides the oral cavity from the nasal cavity. This is present in mammals.
Some mammals are egg-laying. They belong to the Order Monotremata which includes the very known platypus (suborder Platypoda) and echidnas (suborder Tachyglossa). In terms of the size of the unknown species and other classifications, both of the mentioned species fit to it. However, species of echidnas are scaly and the platypus is not. We can finally conclude that the unknown species can be more related to echidnas.