The earliest stromatolites were probably formed by
A. anoxygenic phototrophs.
B. anoxygenic lithotrophs.
C. oxygenic phototrophs.
D. oxygenic lithotrophs.
Answer:A
The earliest stromatolites were probably formed by
A. anoxygenic phototrophs. B. anoxygenic lithotrophs. C. oxygenic phototrophs. D. oxygenic lithotrophs.