Editing Endocerida (section)

=== Evolution ===
Endocerids evolved from the earlier [[Ellesmerocerida|ellesmerocerids]], most likely from a genus similar to ''[[Pachendoceras]]''. This ellesmerocerid gave rise to ''[[Proendoceras]]'', the earliest representative of the [[Proterocameroceratidae]] and hence of the Endocerida. Endocerids evolved from ellesmerocerids by reduction of siphuncle diaphragms and the development of endocones. In the early part of the mid-Lower Ordovician, the Endocerida quickly diversified into many different families. In true endocerids, there was a trend of overall increasing size, eventually resulting in massive orthoconic genera such as ''[[Endoceras]]'' and ''[[Cameroceras]]''. In another lineage (now known as [[Bisonocerida]]), the siphuncle grew more complex, resulting in genera such as ''[[Chihlioceras]]'' and ''[[Allotrioceras]]''.