Evolution: life in the Paleozoic

'Walking with Monsters' is a dramatization of life in the Paleozoic, focused on the evolution of the first plants and animals on Earth. It was produced by the BBC and first aired in 2005. An interesting thing in this dramatization is the use of "wild guesses" in constructing certain behaviors and in linking evolutionary stages, almost bringing the whole enterprise to the realm of pseudoscience. The following document describes briefly evolution during the Paleozoic as featured in the series and commented on several Wikipedia articles (follow the links).

The first episode ('Water Dwellers') is centered on the Cambrian, Silurian and Devonian periods.

Time: Cambrian Period (530 million years ago), in the Paleozoic Era.
Setting: The sea, at the beginning of the Cambrian Explosion.
Main species featured:

Anomalocaris, an ancestral relative of arthropods, yet a genus nowadays extinct.
Haikouichthys, one of the earliest vertebrates and craniates, even perhaps an early fish. (It is introduced as the ancestor of all vertebrates, one of the first "wild guesses" in the series, which also falsely suggests that haikouichthys evolved to become cephalaspis.)

Time: Silurian Period (418 million years ago), in the Paleozoic Era.
Setting: The sea.
Main species featured:

Cephalaspis, an armored jawless fish. (The series introduces the "wild guess" that cephalaspis migrated to fresh water habitats to spawn. It is also falsely suggests that cephalaspis evolved to become hynerpeton.)
Sea sponge, an ancestor of modern sea sponges.
Sea urchin, an ancestor of modern sea urchins.
Cameroceras (identified as Orthocone), an ancestral cephalopod nowadays extinct.
Brontoscorpio, an ancestral marine scorpion nowadays extinct.
Pterygotus, a nowadays extinct arthropod related to arachnids.
Cooksonia, one of the first plants colonizing firm land, yet a genus nowadays extinct.

Time: Devonian Period (360 million years ago), in the Paleozoic Era.
Setting: The coast at Red Hill (Pennsylvania, U.S.A.)
Main species featured:

Hynerpeton, an ancestral tetrapod, a genus nowadays extinct. (The series falsely suggests that hynerpeton eggs evolved into petrolacosaurus eggs.)
Scorpion, an ancestor of modern scorpions.
Oxygen-producing plants and trees, and the formation of the first forests.

(Video 1/9 embedded from YouTube on 28 October 2011)

(Video 2/9 embedded from YouTube on 28 October 2011)

(Video 3/9 embedded from YouTube on 28 October 2011)

The second episode ('Reptile's Beginnings') is centered on the Carboniferous and early Permian periods.

Time: Gzhelian Age (300 million years ago), Carboniferous Period, in the Paleozoic Era.
Setting: Swampy forests in Kansas (U.S.A.)
Main species featured:

Mesothelae, an ancestor of a family of modern Asian spiders. (The series depicts mesothelae as a giant spider yet this may be wrong. At the time it was confused with megarachne, a sea scorpion nowadays extinct.)
Petrolacosaurus, an ancestral relative of crocodiles, lizards and snakes. (The series erroneously identifies it with the ancestor of modern mammals.)
Meganeura, an ancestral relative of dragonflies, yet a genus nowadays extinct.
Proterogyrinus (identified as an Amphibian), an ancestor of reptiles, yet a genus nowadays extinct.
Arthropleura, an ancestral relative of modern centipedes and millipedes, yet a genus nowadays extinct.
Fern forests.

Time: Artinskian Age (280 million years ago), Carboniferous Period, in the Paleozoic Era.
Setting: Germany, during a time of extreme seasonal weather changes.

Main species featured:
Conifers, an ancestor of modern pines and cypresses.
Edaphosaurus, an omnivorous synapsid, an ancestral relative of mammals, yet a genus nowadays extinct.
Dimetrodon, a carnivorous synapsid, an ancestral relative of mammals, yet a genus nowadays extinct. (The series portrays dimetrodon as an egg-laying, parental, yet cannibalistic animal, although these are just guesses. Other behaviors, such as eating up to 90% of a carcass, being repulsed by excrements and cleaning up intestines before eating are also wild guesses. It is also portrayed as an ancestor of humans, from which we inherited our dentition, as well as evolving into gorgonops.)
Seymouria (identified as an Egg-eating Amphibian), a genus nowadays extinct. (The series portrays seymouria as an amphibian capable of waiting seven months for a chance to eat dimetrodons' eggs.)

(Video 4/9 embedded from YouTube on 28 October 2011)

(Video 5/9 embedded from YouTube on 28 October 2011)

(Video 6/9 embedded from YouTube on 28 October 2011)

The third episode ('Clash of Titans') is centered on the late Permian and early Triassic periods.

Time: Changhsingian Age (250 million years ago), Permian Period, in the Paleozoic Era.
Setting: Siberia, during the time of the supercontinent Pangaea, covered by a vast and inhospitable desert.
Main species featured:

Scutosaurus, an ancestral relative of modern turtles, yet a genus nowadays extinct.
Gorgonops (identified as Gorgonopsid), a carnivorous therapsid, a genus nowadays extinct. (The series depicts gorgonops as preying on scutosaurus, which is possibly incorrect, as the latter lived in what is now South Africa. It is also depicted as equipped with deadly weapons never seen before, as if they had evolved by gorgonops just then and there.)
Diictodon, a small herbivorous dycinodont, a genus nowadays extinct. (The series erroneously portrays diictodon as an ancestor of modern mammals, especially one from which the inner ear evolved. It is also depicted as evolving into lystrosaurus, even when both species actually co-existed.)
Rhinesuchus (identified as Labyrinthodont), an ancestral amphibian, a genus nowadays extinct.

Time: Olenekian Age (248 million years ago), Triassic Period, in the Mesozoic Era.
Setting: Antarctica, at a time marching towards the full recovery of conifer forests.
Main species featured:

Lystrosaurus, an ancestral dycinodont, the most abundant terrestrial vertebrate of the epoch, yet a genus nowadays extinct. (The series erroneously depicts lystrosaurus as the ancestor of all mammals).
Euparkeria, a small reptile, an ancestral relative of the future dinosaurs, yet a genus nowadays extinct. (The series erroneously depicts euparkeria as the ancestor of all dinosaurs.)
Euchambersia (identified as Therocephalian), a carnivorous ancestral relative of mammals, a genus nowadays extinct.
Proterosuchus (identified as Chasmatosaurus), an ancestor of modern crocodiles, yet a genus nowadays extinct.

(Video 7/9 embedded from YouTube on 28 October 2011)

(Video 8/9 embedded from YouTube on 28 October 2011)

(Video 9/9 embedded from YouTube on 28 October 2011)

Editor

Jose D PEREZGONZALEZ (2011). Massey University, New Zealand (JDPerezgonzalez).

Want to know more?

Wiki of Science - Simulation (list of topics): This Wiki of Science page provides access to other simulations in science.
Wikipedia - Walking with monsters: This Wikipedia page offers more information about the series and accompanying book.

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