[WillPS]

As for the Saturday afternoon CBBC on Choice, I don't think that ever had studio links. It was just a regular continuity announcer over the CBBC in Choice idents

The early Saturday afternoon stuff was branded CBBC Choice. The later proto-Cbeebies daily loop, with studio links, was referred to as CBBC on Choice (and just branded CBBC on screen).

[Tola]

up.metropol247.co.uk 

I did watch at least part of some early episodes, though given it was merely linking material between various CBBC shows, being not too bothered about the programmes it was linking I didn't see much point in tuning in regularly.

It was in fact the second programme in that Saturday lunchtime slot, having been preceded by something even more obscure called The Crew Room, which I never saw as it ended before I even had access to digital television: genome.ch.bbc.co.uk 

There's also another image of the show on the Adam's nostalgic memories blog as well as an article on it:
   
www.broadcastnow.co.uk 

The Dog & Dinosaur Show is BBC Choice's new children's programme, presented by t…
The Dog & Dinosaur Show is BBC Choice's new children's programme, presented by t…
  Source: www.broadcastnow.co.uk

The two characters apparently judging from that article were produced by the US based computer animation company "Protozoa", and started around March 1999. It had stopped airing around late April 2000 (going by BBC Genome)