Diadectomorph

The diadectomorphs are a group of extinct land vertebrates that show both amphibian and reptilian features.
They lived in the epochs of the Upper Carboniferous and the early Permian on the supercontinent Laurussia.
They include large, up to two meters long and partly aquatic carnivores like Limnoscelis, and also the first large, herbivorous land vertebrates.
Diadectes was three meters long, had a highly specialized skull with a secondary palate and molariform teeth, so it is assumed that it fed on hard plants.

The diadectomorphs are known for being either the closest relatives of the amniotes, the group that includes reptiles, birds, and mammals, or the earliest members of the synapsids, the group that includes mammals and their extinct relatives.
They have typically been classified as advanced reptiliomorphs, transitional between "amphibians" sensu lato and amniotes, but some recent research has recovered them as the sister group to the traditional synapsids within amniota, based on inner ear anatomy and cladistic analyses.

The diadectomorphs are also known for their diverse adaptations to different ecological niches.
They are divided into three families: the diadectids, the limnoscelids, and the tseajaiids.
The diadectids were medium to large herbivores with chisel-like teeth and strong legs.
The limnoscelids were large carnivores or piscivores with pointed and slightly curved teeth.
The tseajaiids were medium-sized, generalized reptiliomorphs.

• The Diadectomorphs were among the first tetrapods to adapt to a herbivorous diet, and had chisel-like teeth that could grind tough plant material.

• The Diadectomorphs were also among the first tetrapods to develop a strong and upright posture, which enabled them to move faster and more efficiently on land.

• The Diadectomorphs are classified into three families: Diadectidae, Limnoscelidae, and Tseajaiidae, representing different ecological niches and body plans.

The diadectomorphs were a group of ancient beasts
That lived in Euramerica and Asia in the east
They had both traits of amphibians and reptiles too
And some were big and plant-eating, while others meat they chewed

Some looked like giant salamanders with long and slender tails
And others had robust and sturdy legs with strong and horny nails
They had different kinds of teeth, some flat and some with folds
And some could reach up to three meters, as the fossil record shows

They lived from late Carboniferous to early Permian times
And they survived the rainforest collapse and many climate changes
They were among the first tetrapods to conquer the dry land
And they were close relatives of amniotes, the group that we belong

So if you want to see a picture of these creatures from the past
You can check out the links I've given you, or use your imagination
But don't expect them to be cute or cuddly, for they were not like that
They were diadectomorphs, and they ruled their habitats