Scientists on Wednesday announced they can now give the world a new picture of Hallucigenia sparsa, a sea oddball that was so strange, it looks like something out of a hallucination or nightmare.
Hallucigenia has been found in Burgess shale-type deposits in Canada and china, as well as in isolated areas around the world. It gets its strange name from some often quirky studies, as well as its strange appearance. When the animal was first reconstructed, it was upside down and back to the front.
“It is nice to finally know rather fundamental things such as how many legs it has, and to know its head from its tail,” University of Cambridge paleontologist Martin Smith said.
Hallucigenia is now recognized as a “lobopodian worm,” and is considered by some scientists to be an early ancestor of our living velvet worms. Then again, some researchers consider them to be closer to arthropods, perhaps because the velvet worm is a close relative of arthropods.
Hallucigenia is one of the animals that is emblematic of the middle Cambrian Period on Earth, living about 508 million years ago. This was a time when many major animal groups first appeared, and many strange body designs came and went as life continued to evolve.
It is now known that Hallucigenia, 0.4 to 2.2 inches long (10-55 mm) had seven pairs of nail-like spines sticking out from its back. On its underside, it had an equal number of flimsy legs, tipped with claws. There were three pairs of very thin tentacles near the head. Scientists are unclear if these tentacles aided in processing food or were used as antennae.
It is funny now, but when the fossils were first examined, a large balloon-like orb at one end of the body was thought to be the head. It has now been discovered that this was not part of the animal at all. “It was a blob of decayed fluids that had oozed out of the anus during decay and burial,” said Smith.
Using sophisticated imaging techniques, scientists were able to ascertain the head was actually at the end of a long, tube-like neck. Near the end of the head were two bean-shaped eyes. “Below the eyes, like an almighty grin, sits a ring of teeth,” Smith said.
Smith went on to describe the eating process, saying in front of the teeth was a small mouth cavity used to such food into the throat. Once food reached the needle-like teeth, it was chewed up, helping the digestion process along. “It would have been quite a sight,” said Royal Ontario Museum paleontologist Jean-Bernard Caron.
This research was published in the journal Nature on June 24, 2015, under the title; Hallucigenia’s head and the pharyngeal armature of early ecdysozoans.
