The Strangest Trilobites
The diversity of body designs presented by the trilobite class is nothing less than astonishing. In size, shape and appearance, few creatures that have ever existed display the degree of morphological variance exhibited by these Paleozoic arthropods.
Trilobites survived for over a quarter of a billion years -- plenty of time for them to develop into the more than 25,000 species so-far recognized by science. But amid that mind-boggling variety of trilo-types, there exist a number of species that are so unusual, so strange, so out-and-out bizarre that they deserve special mention. These are creatures so alien in appearance that they could easily serve as featured attractions in any Hollywood sci-fi spectacular -- but few observers would believe that such out-of-this-world life forms could actually exist. But they did… and they were among the first rulers of the earth's seas.
Imagine the likes of Actinopeltis globosus, a trilobite with a perfectly symmetrical “ball” perched on its glabella. Picture others such as Walliserops trifurcatus with a trident-like fork extending from the front of its cranadium… or Asaphus kowalewski with eyes sitting atop two-inch long stalks… or the aptly-named Dicranurus monstrosus with two monstrous “horns” sweeping back from the top of its cephalon… or Cyclopyge bohemica which possessed a single eye that literally wrapped around the entire front of its head.
Indeed, the multitude of trilobite body designs are almost difficult to fathom -- even for those who have grown extremely familiar with these primeval aquatic inhabitants. And amid those designs are some that even the likes of Salvador Dali would have had difficulty envisioning; Erbenochile issimourensis, which actually developed a shading “brow” atop it's thick inch-long eye stacks, Odontocephalus ageria with a frilled “cow-catcher” emanating from the front of its cephalon, and Asaphellus cuervoea with genal spines so long that they may have functioned like “wings” allowing this species to sail through the warm tidal estuaries it called home.
Scientists agree that these varied and unusual morphological features benefitted their host trilobite in some significant manner during the creature's daily quest for survival. It has been speculated, for example, that the “ball” atop the nose of Actinopeltis may have been used as a flotation device while the trilobite was navigating rough seas. But others surmise that the same anatomical feature might well have functioned as an egg sack. The trident attached to Walliserops may have served a variety of purposes: an anchor during storms… a grasping device while mating… a defense mechanism… or even a tool used to aid feeding.
Whether or not we ever discover the true functions that these incredibly bizarre bodily features served, the undeniable conclusion we reach is that trilobites were amazingly adaptable creatures, animals capable of evolving rapidly and effectively in order to maximize any ecological advantage. And while eye stalks, nose sacks, tridents and horns may seem incredibly unusual to us, the fact is that such developments allowed trilobites to exist for nearly 300 million years and leave behind a fossil legacy that perhaps no other creature can equal.
Here's a look at some of the strangest trilobites in the fossil record:
The Ordovician trilobite Actinopeltis globosus presented what appears to be a ball on its nose, a feature that might have been used for flotation.
The Russian trilobite Asaphus kowalewski had eyes perched atop two-inch long stalks.
Walliserops trifurcatus is a Moroccan trilobite that presented a trident-like fork emanating from its cephalon.
Dicranurus monstrosus possessed two ram-like horns that swept back from its cephalon.
Odontocephalus ageria, found in the Devonian rocks of Pennsylvania, utilized a cephalic extension that resembled a cow-catcher.
Not only did Erbenochile issimourensis possess some of the largest eyes in the trilobite world, but it also developed a pronounced “brow” to help shade them.
The Moroccan trilobite Asaphellus cuervoea had wing-like genal spines that may have allowed it to glide through ancient seas.