You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Mammal

Context:
Most mammals are viviparous, giving birth to live young. However, the five species of monotreme, the platypuses and the echidnas, lay eggs. The monotremes have a sex determination system different from that of most other mammals. In particular, the sex chromosomes of a platypus are more like those of a chicken than those of a therian mammal. Like marsupials and most other mammals, monotreme young are larval and fetus-like, as the presence of epipubic bones prevents the expansion of the torso, forcing them to produce small young.

Question:
The platypus has sex chromosomes more related to which other non-mammal?

chicken