Most likely they are. There isn't much free oxygen there either, I would imagine. Otherwise, every spark of static electricity would give the astronomers something to ooh and aah over.
The reality is that every oil deposit on Earth has been found in association with rock rich in organic material from biological activity. While it may have migrated from that source rock to a better reservoir, the origins remain biologically linked.
I'm not sure where the dinosaur canard came from, but algae and plankton are the most common fossils involved, along with a host of marine, and more rarely freshwater invertebrates.
/johnny