Striped Hellasic Dyle

Pedicambulata are a clade of periostracans somewhat related to the bennus, but instead of staying bipedal, these creatures developed their tunicine tail into an insect-like third leg. You may have already met a member of this clade in form of the Caraxor, but this creature obviously derived the three-limbed condition even further. A more classic example of pedicambulates are the dyles, which are widespread on Mars. The most famous one, at least for Earth-readers, is likely the striped dyle of Hellas Planitia, due to its pattern. Similar to zebras, each individual of this dyle species has a slightly different pattern, which probably helps herdmembers identify each other. Though, again like with zebras, we do not know for sure the true function of the stripes. A social function seems likely, but they could also help break up the animal’s silhouette in tall vegetation or aid in thermoregulation (or all of the above). Tests done on the related ilthu indicate that this species can see in ultraviolet and this may very well apply to other pedicambulates, which could mean that these animals also have a hidden UV-coloration we are not able to perceive.

 Fig. 2: The hellasic dyle (with extended proboscis) in comparison with an astronaut. Petting dyles, no matter how fuzzy their fur looks, is not recommended, as the scissor-like scolecodont-edges can tear through spacesuits.

Dyles are generally small browsers and grazers, using their rake-like scolecodont-tips to strip tall-growing fractarian flora, which they cut further with their sharp tooth-edges. On average, dyles are slightly larger than herbivorous deltadactylians, with whom they seem to compete for resources. Unlike these derived onychognaths, dyles also sport a fully endothermic metabolism, which likely aids in niche partitioning, as this means the deltas require less food. Why both pedicambulates and deltadactylians convergently evolved tripodality, even if in a different configuration, has been asked since the early days of Martian astrobiology. Ultimately, it may just come down to coincidence, though the evolution of a third leg in the former is much more reasonable than in the latter.

The striped hellasic dyle lives in small family groups. These often gather once a year in colonies to find a suitable mate, build a nest and lay and hatch their eggs. Once the young are old enough to walk on their own, they follow their parents on nomadic journeys across the savannah, until they are themselves old enough to found a family. Despite their parents’ care, usually only one or two individuals will reach adulthood out of ten or so eggs. The inner shell of these young is still fragile, making them good targets for various predators in the savannah. These range from creeping things like serpentine onychognaths, thecocerates, and zhors to predatory nothornithes and other pedicambulates, like the irsu or the flying, stork-like vhagator. Although not large enough to eat them, trichordates can also be dangerous, as some species have evolved defensive venom-spikes in their arm-tips to deter larger animals from eating or stepping on them. Often these have obvious warning colours, but not every youngster is smart enough yet to get that message.