what are the origins of the southern ones?
The history of southern constellations is not straightforward.
Constellation
The history of southern constellations is not straightforward. 
what is leo minor? It is a small and faint constellation. who found it? Johannes Hevelius when? 1687 which stars are a part of it? 46 Leonis Minoris, Beta Leonis Minoris, 21 Leonis Minoris can you name a few of its characteristics? It is a small constellation, its area covers 232.0 square degrees of the sky, culminates each year at midnight etc the person who found this, did he find any other star? UNANSWERABLE the person who found this, where was he born? UNANSWERABLE what is a group of stars called? Constellation how many modern ones are there? 88 how are they identified? By the pattern of stars can you name a few? Pleiades, Hyades, Big Dipper etc
wiki:1584943
Constellation [SEP] Origin of the southern constellations
The southern sky, below about −65° declination, was only partially catalogued by ancient Babylonians, Egyptian, Greeks, Chinese, and Persian astronomers of the north. The knowledge that northern and southern star patterns differed goes back to Classical writers, who describe, for example, the African circumnavigation expedition commissioned by Egyptian Pharaoh Necho II in c. 600 BC and those of Hanno the Navigator in c. 500 BC. However, much of this history was lost with the Destruction of the Library of Alexandria. The history of southern constellations is not straightforward. Different groupings and different names were proposed by various observers, some reflecting national traditions or designed to promote various sponsors.