“Late in the afternoon, a lone male Eoceratanoderes walks through a small Floridophycean forest in what will one day be southwest Tlèëa. A trio of Spikechin “flish” flies by while an inconspicuous Archeoglossgnathus yawns, as she wakes up for a night of hunting.”
Roughly 145 million years ago, Eryobis was a very different place.
There were no Stauropterygians, no Enantiopterans and no Skysquirts filling the air. Back then the continents laid very different and all land vegetation was still exclusively shades of red.
This was the Björnbergian stage of the Bobossic period. During this time, many things started to change. The last remnants of dominant fauna from the Phylloceous had faded away or had been replaced by newer generations as the climate shifted.
The old generation of megafaunal herbivores had started fading away. In the gap they left behind, a more advanced type of herbivore arose: the Ceratanodirids. These were medium to large sized herbivorous Brachiostomatan Anisospondyls, often characterised by having a single horn located behind the eyes, in front of the visendal spiracle that were the dominant megafaunal herbivores of the last 30 million years of the First Era. Of this lineage, Eoceratanoderes was among the very first to develop the characterising horn. Standing roughly 70 centimetres tall at the withers, it was quite small compared to its later relatives, but already showed most of the characteristics that would make this family so successful.
145 million years ago, there were no flying Anisospondyls yet. Instead, another kind of vertebrate ruled the skies and had a monopoly on it until the sky itself burned. Often referred to as “flish”, these animals lack a scientific name for they are not a natural group and instead appear consist of at least 2 lineages that independently evolved flight. By far the most successful were the “regular flish”: seemingly typical octopodichthyian spiderfish with enlarged pectoral fins for wings. The species depicted here has evolved a bright blue face for display and a sharp beak and chin spike prying open “bark” to find Cyclopsfly grubs.
But of the three species of vertebrates depicted, only one has living descendants. The small lizard like animal called Archeoglossognathus, was among the earliest representatives of todays dominant kind of terrestrial vertebrates: the Cryptognathan Anisospondyls.
Anisospondyls with their horizontally oriented mouths face one great problem as they grow larger: gravity.
When eating, gravity has a tendency to let the food fall out of the horizontal jaws of Anisospondyls. The earliest Anisospondyls as a result stayed close to the ground, but as plants grew taller, them growing as well was inevitable. Large, fleshy lips have evolved multiple times to prevent food from falling out, but this wasn’t enough for early Anisospondyls. Brachiostomes like Eoceratanoderes turned their caecal front limbs into food manipulating appendages located directly below the mouth to both prepare food and catch anything that might fall out.
Cryptognaths are one of the two surviving lineages of advanced Anisospondyls and are without a doubt the most diverse. They derive their name from the second set of jaws they have hidden within their throats. These jaws are in essence the ossified tip of the tongue and the no-longer-attached-palate sown together by muscle and ligaments. This second set of jaws is used for a wide range of purposes such as holding- and tearing off small chunks of food.
During the Björnbergian, Crypognaths remained small and insignificant under the shadow of the Brachiostomes. But 30 million years later, at the end of the Kikilian epoch, more than 90% of the latter will die out and Cryptognaths will claim the throne as the new dominant vertebrates on land…although not without resistance…
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