palaeozoic

This will be the first post in a series of gifs, going through the geologic periods, from the palaeozoic (time before the dinosaurs, 541 to 252 million years ago ) and the mesozoic (time of the dinosaurs, 252 to 65 million years ago) and highlighting the various pokemon that would have been around during those times.

We begin with the Cambrian Period, the first period of the Palaeozoic era, i.e. the first era from which diverse and visible life could be found. Most of the major animal groups, or phyla that have ever existed made their first appearance in the Cambrian. Land at the time was completely barren, however, shallow seas were rich and abundant with diverse life.  Hard animal parts - for example shells for protection, claws/pincers for hunting, also made their first appearance in the Cambrian, marking the beginning of true predator/prey interactions and evolutionary arms races.

The following pokémon may have been found during this period:

- Anorith/Armaldo - based on Anomalocaris, a ferocious cambrian predatory arthropod (so, related to modern day insects, crustaceans etc) with large well developed eyes for hunting, and two formidable claws lined with barb like spikes, positioned in front of it’s mouth. 

-Goomy - Goomy may be based on Wiwaxia, which is possibly the earliest mollusc (slugs, snails, squid etc), and one of the earliest examples of the use of shelly scales as defense

-Other pokemon - ancestors of the jellyfish pokemon would likely have been present. If kabuto/kabutops are counted as trilobites, then they would have been present too (But I count them as horse shoe crabs, and kabutops possibly as a  sea scorpion, both of which appear a wee bit later)

anonymous asked:

What is your favorite Paleozoic creature?

Whew!  there are so many awesome animals all across this era, it gets real hard to just settle for a single favorite! I gotta admit too, as much as I love the obscure little lovelies, I am not very original when it comes to absolute favorite Paleozoic creatures XD. With that confession out of the way, I’d say it’s pretty much a three-way-tie between these:

Inostrancevia alexandri (specifically alexandri because it’s the type species and pretty complete!)

(source)

Arthropleura armata (Yes I went for the largest species, like I said, I’m not very original XD)

(Stuttgart Museum of Natural Sciences)

Dunkleosteus terrelli (… someone’s gonna faveshame me I bet XD)

(source)

youtube

Palaeocast lunchtime lectures - Trilobites - Evo-Devo on a Roll - Prof. Nigel Hughes

The good record of postembryonic development of the trunk region of some trilobite species permits investigation of how mature body form was constructed. The trunk was built progressively via the expression of new exoskeletal segments in a subterminal generative zone, and by their growth and development in subsequent instars. This permits insight into the relationship between the ontogenies of individual taxa and clade history. The controls of trunk segment growth may be explored in order to understand how segment differentiation was determined in early arthropods. Trilobite trunk segments varied from one another in size, shape, and articulation state, and clade evolutionary history suggests a repeated tendency towards greater morphological differentiation within the trunk, along with allocation of a larger proportion of trunk segments to the mature pygidium. This was paralleled by the evolution of secured, encapsulated enrollment. Enrollment in those individuals with small numbers of articulating segments accommodated considerable flexure at each joint, which show differences in form from those joints within segment-rich thoraces. While the developmental evolution of trilobites retains rich research possibilities, we posit that both biomineralization and encapsulated enrollment enhanced protective capability, and that adaptive response to predation pressure was an important driver of trilobite evolution.

Amphibian August #04 – Sclerocephalus

And now it’s time for temnospondyls!

One of the most successful tetrapod groups of the late Palaeozoic and early Mesozoic, temnospondyl amphibians first appeared 330 million years ago and flourished for the next 210 million years, being found on every continent occupying a diverse range of habitats. And, depending on who you ask, they might even still be around today in the form of modern amphibians – but we’ll talk more about that later on in the month.

Sclerocephalus lived during the Late Carboniferous of Germany (~301-297 mya), and grew to around 1.5m long (4′11″). It’s known from many well-preserved fossil specimens, some of which show soft tissue impressions and stomach contents, and we even have evidence of its complete life cycle from larvae to metamorphosis to full maturity.

Juveniles were slender-bodied with external gills and longer tails, preying on small crustaceans and plankton. As they grew and metamorphosed, they lost their gills, strengthened their skeleton, and bulked up their limbs, moving to a diet of fish and other amphibians.

Unlike modern amphibians Sclerocephalus and some other temnospondyls were also scaly, although it’s important to note that these were much more like fish scales than those of reptiles. There would have been a layer of skin over the top, and the scales probably wouldn’t have been particularly visible in life.

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Also, found a real root fossil (lileep and cradily!) in some Carboniferous limestone beds today. Sea lilies, or crinoids, are not in fact plants but essentially starfish on stalks. They were hella widespread for most of the Palaeozoic (before dinos) and during the Mesozoic (dino period) but are a lot rarer nowadays, with some deep water forms, and including modern day feather stars, which have lost the stalk :)