What if Mars never had liquid water?

For there to have been rivers of liquid CO2 on Mars it would have needed an atmosphere that is about 5.2 times that of Earth's atmosphere. In fact for there to have been rivers of CO2 flowing in order to carve out the river beds would require 518 kPa at −56.6 °C as that is the tripple point of CO2.

That's what conditions would have been like on Mars if it was liquid CO2 that carved out the channels.

By the way Carbon Dioxide is what I assumed you meant by Co2 (the O should be capital) because it's one Carbon atom and two Oxygen atoms and Oxygen is an element. Co2 is a molecule consisting of two cobalt atoms. Obviously for rivers of liquid cobalt we'd need exceedingly high temperatures, to smelt the cobalt out of the rocks in which case the whole Martian surface would be molten and therefore there wouldn't be channels so I'm certain you meant CO2 not Co2.

If mars had liquid co2 the clay would be a different color because its the same color as earth clay and earth has liquid water. Plus co2 absorbs heat so it would be more like Venus than the current mars like state

If Mars never had water, the geological features (rocks) would have Carbon Dioxide trapped in them instead of oxygen.

Since they haven't actually "found" H2O on Mars yet (there is simply some geological evidence to suggest Mars had water on it at one point in it's history) your question is quite pointless.

interest has measured temperatures on Mars. they vary from some levels above freezing (Celsius 2-4 levels) to approximately 80 levels below freezing. i've got have been given faith any substantial physique of water ought to be frozen.

liquid co2? What would that even look like?