This is the interpretation of the Saymaly-Tash petroglyphs (the earlier layer) given by Y.A.Scher.
Some of peculiarities of the pictures (different animals harnessed in chariots) can be explained on the basis of the IE
mythology
and ethnography.
Ashvins literally are connected with horses and usually they are described in Rigveda on the chariot with horses. However in
some hymns their chariot is carried by bulls, donkeys, falcons, swans, ox and crocodile (RV I, 116, 18). In all probability
non-horse chariots are most archaic.
At the wedding of Surya and Soma a chariot competition took place. Agni drove mules, Ushas drove red bulls, Indra drove horses,
Ashvins drove donkeys. (To my mind more logically would be to give bulls to Indra and horses to Ashvins or Agni).
The Greek myth of Admet and Alkesta tells how Apollo succeed to harness a lion and a boar in a chariot.
There are different ancient Greek artifacts picturing chariots with lion and boar, horse and sphynx, deer and sphynx, 2 goats,
or 4 animals - lion+panthera+2 deers.
Lithuanian Perkunas and Tor in Edda drive chariots with goats.
Hittite describing of a royal ritual mentions a vehicle (apparently a chariot) with a horse (right) and a mule (left).
Data on the Freya's chariot with cats can be added to this.
There is a later layer of the Bronze Age petroglyphs in Saymaly-Tash: typical IE chariots with horses in "plan composition" like
Scandinavian or Sibirian ones. Apparently they are made by the bearers of the Andronovo culture (they seem to be Iranians).
Therefore the earlier layer is made by people of IE branch, which split off the main IE massif earlier than Indo-Iranians and
other groups, i.e. aproximately as early as Anatolians did. They could belong to the same earliest wave of IE, which brought
bearers of the Afanas'yevo culture to Yenisei. As we can see they did not have real war chariots (Iranians did), but chariots as
a 2-wheeled vehicle already appeared. Apparently they were used in the beginning not as a transport (they were to small) but as
a sacral thing. Maybe such a chariot was just a way to roll a wheel (symbol of the Sun) with the help of animals (in this
situation no matter what kind of animals). Only later in the main massif of IE the war chariots were (accidentally?) invented.
This is my speculation.
Besides pictures with the chariots and 'cowpokes' I've attached 2 more pictures of the same layer. Can we find parallels to
their subjects in the IE mythology?
Alexander Stolbov
http://siem.newmail.ru