Birds and Their Evolutionary Relatives
Birds are more closely related to reptiles.
Why
- Evolutionary History: Birds evolved from a lineage of theropod dinosaurs, a group of reptiles. This is supported by fossil evidence and genetic analysis.
- Shared Features: Birds and reptiles share:
- Amniotic eggs: Both lay eggs with a protective membrane (amnion).
- Scales: Birds have scales on their legs, homologous to reptile scales.
- Similar skeletal structures: Bird wings are modified reptilian forelimbs.
While birds and mammals share characteristics like being warm-blooded and having a four-chambered heart, these traits developed independently in each lineage.
Therefore, the evolutionary relationship between birds and reptiles is much closer than that between birds and mammals.