Aha - I wasn't sure from the cover as the Yazirian didn't have wing flaps. Sometimes you just can't tell if sci-fi art from that period isn't cashing in on Wookies in some way ;)

In addition, there are other large, dangerous animals which are briefly mentioned, but not seen or named.

Villains of Volturnus

This book is basically a continuation or epilogue for the Volturnus series.  It happens a few years after the war, and could very easily be made into a module.

One of the megacorporations (Universal Minerals) has hired pirates to illegally seize the mineral wealth of Volturnus.  In the story, there are pirates & corporate goons working together.  In addition to the Core Four, we also see Kurabanda working for the megacorp.  Of course, this megacorp is later proven to have connections with the Sathar.

The existence of the Eorna is general knowledge, and kids study their civilization in school, but no one is aware that the Eorna are still alive.  People believe they are extinct.  No Eorna or Mechanons are seen in the story, but the main character does explore an abandoned Eorna city (with some nice pictures of it). 

Larger commercial ships, such as passenger vessels, include small, spherical escape pods known as "Personal Safety Pods", or PSPs.  They use atmospheric rockets to slow your descent as you land.  I have incorporated these into my game.  They are only designed to hold a few humanoids, or 2 Vrusk.  They include food & water, and an automated radio beacon (just a beeper, no ability to send messages).  There is a gauge that gives you an external atmosphere & temperature reading, to tell you if it is safe to open the pod.  One very nice feature is that PSPs come with a collapsible hovercycle.

Ships have special seating for Vrusk. 

Dralasites only use arms & legs when they need to, and otherwise take a somewhat spherical shape.  Dralasites ships & cities use ramps instead of stairs. 

Interstellar radio transmitters are described as large & bulky.  They are not available to the general public (which is consistent with Captive Planet), and require a special key to operate.  Inserting the personal radio key, which is crystal-based, into the radio transmitter allows you to send & receive messages on your own personal, private radio frequency, and the key remembers your individual settings.

The Volturnian sky is described as greenish, and the climate is described as being too dry to start fires because it might spread easily.

We see Edestekai, Ul-Mor and Kurabanda, all of whom are now familiar with the different species of the Frontier.  Their depiction is consistent with the Volturnus modules.  Kurabanda are wearing the same sorts of clothes as the Core Four, implying that they are becoming a part of Frontier life.  A Kurabanda and a Dralasite constantly exchange jokes, which annoys their human co-workers.

The main character carries a microreader, which is something like a portable microscope, not much bigger than a pen.  It allows the user to look through it and read microreader discs.  You can carry quite a few of these tiny discs with you.  Anyone who has read Heinlein should be familiar with these, because he uses them in his stories quite often.  Because it has its own light source, the main character uses it as a kind of penlight in dark caves.