No. An 80487 would have been a math coprocessor for an 80486
general-purpose microprocessor...just like the 8087 was the math
coprocessor for the 8086 and 8088, the 80287 for the 80286, and the
80387 was for the 80386. The 80486 was the first Intel processor to
contain an on-chip math coprocessor, so there wouldn't have been an
80487 because it wasn't necessary.