Ratha's Creatures - What are the "barking raiders"
In Ratha and Thistle-chaser, Book 3 of the Named, Newt (later called Thistle-chaser), fights a brief but intense battle with a pack of "barking raiders" who attack Splayfoot, the seamare (Paleoparadoxia - see previous post.) What are these creatures? Are they also based on fossil animals or is the author making things up?
Like all the other creatures that appear in Ratha's world, these yelping raiders also existed in the early Miocene. Those readers who put things together quickly, i.e. a beach dwelling animal, bulging eyes, a swimmer, barks, has flippers, etc. have already guessed that these animals are seals or sea-lions. Good call, except that seals and sea-lions as we know them today hadn't yet evolved 20-25 million years ago. However, their precursors did exist. When Newt rushes down onto the beach to defend Splayfoot, she encounters Enaliarctos, the early ancestor of the present California and Pacific Coast sea-lions.
Here is the begining of the scene from the book (pp. 36-37):
On the beach in the cove below, she saw Splayfoot
with her two seafoals huddling at her sides. Five
small animals with sleek, wet pelts and sinuous
shapes surrounded and menaced the family. These
small sea-lions reminded Newt of the otters she
had seen in the ocean, lolling in wave troughs.
The otters swam with webbed toes and long, powerful
tails, whereas these animals had clawed flippers
and much shorter tails. Their ears were small and
lay close to their heads, and their eyes bulged.
Their muzzles were tapered, with powerfuljaws
Of course, sounds don't fossilize, but being a sea-lion ancestor, Enaliarctos probably made the unique (and loud) sea-lion bark that echoes from many Pacific beaches and sea-washed rocks.
"Newt's opponent barked at her with a blast of fishy breath, then scooted free to bite her on the tail."
Ouch! She's lucky she didn't get an infection in the wound, since seal and sea-lion teeth can carry some nasty bacteria. Pinniped hunters and handlers, if not careful, often develop a stubborn inflammation called "seal hand".
From careful study of Enaliarctos fossils, paleontologists have developed a description of a creature that looks and lives a lot like an otter, although probably a descendent of the amphocyanid "bear-dogs" (see Ratha's Creatures - Bristlemanes). Serum albumin (protein) studies have placed sea-lions slightly closer to the bear Ursus, and seals slightly closer to the California sea-otter, Enhydra. Other studies indicate that the pinnipeds (seals, sea-lions and walruses) are more closely related to each other than any non-pinniped carnivore family. One depiction of pinniped family relationships shows seals descending from otter-like mustelids (weasels) while sea-lions arose from dog- and bear-like ancestors.
Below is an artist's interpretation of the animal (painting by M.R. Long in Mammal Evolution, by Savage and Long. This is an excellent book, though hard to find. It deserves reprinting.) This image influenced my description of the "barking raider" in the book; another instance of how art and writing interact.
The study of pinniped evolution also shows a split by location, with each side dominating their own ocean. Sea-lions, and their close relatives, the walruses, took the Pacific, while the seals made the Atlantic their own swimming pool. Later, some walruses crossed over to the Atlantic and some seals entered the Pacific.
Eniliarctos' head in particular, resembles a modern-day sea-lion's, with large eyes and enlarged nasal passages (to enhance inhaling and breath-holding for diving). Although external ears don't fossilize (although evidence of ear-moving muscle attachment points might be found on fossil skulls), Enaliarctos may have had small sea-lion-like ears. It also shows a modification of the cerebral circulatory system to impove drainage of blood from the brain while diving. This is also found in present-day sea-lions.
Enaliarctos had an otter-like body, with a reduced tail, as the creature was starting to shift from an otter-like swimming mode (using the tail) to a sea-lion mode (using the rear feet as sculls and the forefeet as flippers).
It still had rear legs that were more otterlike, so that it could bound along on land. Like the short-legged otter, it probably increased its stride by arching and flexing its back.
Next on stage - the blubber-tusker!