1658

• Date unknown - The Sloth Nebula was finally identified as a nebula, as part of Hera Huggin’s “Survey Astrologica.”
• March 11th - Naturalists first described the parchment nautilus. (The native peoples on the islands where the nautilus was found presumably already knew about it.) Males and females display extreme apparent dimorphism, although this is an illusion. The females secrete a thin egg case, which they carry with them everywhere. After the eggs are hatched, they continue to use it to trap air to aid with buoyancy. Because they carry the egg case in a particular fashion, they appear to have a shell. The males are nearly identical, but do not carry such an egg case. The confusion led to them being classified as different species for many years, until they could be studied in captivity.