did dinosaurs shrink and evolve into birds
Did Dinosaurs Shrink and Evolve into Birds?
Chickens, crows, seagulls, and any other species of birds that one can think of, are largely believed to be modern-day dinosaurs. However, did the dinosaurs actually shrink and evolve into birds? Let's take a look at some facts related to this fascinating theory, and attempt to reach a feasible conclusion.
Also, the skeleton sizes became consistently smaller, with the passage of time. Excavations in China, during the 1990s, uncovered numerous fossils of what appeared to be dinosaurs covered with fuzzy feathers or quills, which has strengthened their case even further. All these clues are indications of how dinosaurs became birds. These facts were accepted by a large part of the science community as proof of evolution. However, there is another group of researchers who disagree with this theory.
Criticisms of the Theory
Scientists conducting research found that, there were a few important points of differences between dinosaur and bird bodies, which made it unlikely that the evolution theory of dinosaurs turning to birds is true:
- The accepted fact is that, all dinosaurs were reptiles, and by extension, cold blooded creatures, while birds are known to be warm-blooded. Change from cold-blooded body systems to warm-blooded systems is unprecedented, nor is there any proof to suggest that dinosaurs were actually warm-blooded, which is a major obstacle to the evolution process.
- While supporters of the evolution theory display the three-fingered hand structure of dinosaurs to be similar to birds, the fact is that of the five fingers; dinosaurs retained digits 1, 2, and 3, while birds retained digits 2, 3, and 4.
- The lungs of birds facilitate unidirectional airflow, unlike the bidirectional (air goes in and out using the same path) airflow of mammals. Although soft tissue is rarely found in dinosaur fossils, the ones which do, clearly show that their lungs were bidirectional in nature, rather than unidirectional like a bird.
- A major blow to the evolution theory was the fact that, archaeopteryx fossils were much older than some dinosaur fossils, which is not possible if dinosaurs evolved into the archaeopteryx, before finally turning into birds.
- It was also found that, all dinosaurs would run or walk using their hips, but birds move using the knee joints, while the hips remain largely stationary. While this does not seem very significant a change, the fact is that, the immobility of a bird's hip keeps its lungs from collapsing, which seems to contradict the dinosaur-to-bird theory.