#synapsida

[mariolanzas]

SYNAPSIDA 

Some of the animals featured in my YT video on Synapsids, many more are included there. This piece is now also available HERE for prints and more

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Youtube Channel

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Prints and more items of my artwork

[sina-man]

Speculative baby placerias with egg tooth

[ornithopsis]

It's been a long time since I've posted on here. Here's a rough sketch of a Tetraceratops.

[harpagornis]

Did multituberculates and co have a corpus callosum?

Filikomys reconstruction by Misaki Ouchida. Multituberculates are now thought to have been intelligent mammals, so this discussion is worth having.

Modern placental mammals have something marsupials and monotremes lack: a corpus callosum. This allows for connectivity between the brain hemispheres and thus higher intelligence (though marsupials might be more clever than we give them credit for, and birds lack a corpus callosum and are next in line for civilization). Its thus worth to ask: did extinct non-placental groups have a corpus callosum?

On one hand, the fact that only placentals out of all amniotes have one would imply that this is a feature exclusive to them. On the other hand, marsupials and monotremes both produce undeveloped, fetal young, so they could have secondarily lost the corpus callosum as part of their simplified development. Extinct groups like multituberculates not only were as intelligent as placental mammals but had parts of their braincase not seen in other mammal groups, so it's not unreasonable to assume either the corpus callosum was a mammal synapomorphy and lost on multiple groups or it developed independently. Or maybe multies and co didn't have one and simply got smart via other ways like birds.

Hopefully future finds (or genetic and developmental studies in living mammals) answer this.

[animaraptor]

Mesenosaurus romeri, extinct monitor-like small varanopidae (synapsida?) from USA (Oklahoma) and Russia (Arkhangelskaya oblast).

[archipithecus]

found a decapitated wild rabbit in a neighbor’s yard, pics under the cut

[sabertooth-showdown]

GENUS: INOSTRANCEVIA

(no common name available)

LONGEVITY: About 6 million years

DISTRIBUTION: Isolated (European Russia only)

NOTABLE ATTRIBUTES:

Huge size makes it resistant to damage and very intimidating

Jaw morphology suggests high bite force, something not characteristic of sabertoothed predators

Double-edged serrations on all teeth, including canines and incisors

Tooth regeneration

Large, sturdy skull capable of withstanding high stress

WEAKNESSES

Lower speed and maneuverability due to semi-sprawling stance

Poor stamina due to lower metabolism than true mammals

Low intelligence

Only has one reliable weapon (jaws), as its limbs were not strong or flexible enough to be used in climbing or combat

Inostrancevia was an absolute powerhouse of an animal, and at 11ft long, one of its species may have been the largest sabertoothed carnivore ever. At first glance, inostrancevia is an easy high tier, but when one takes a closer look some glaring inadequacies become apparent. While its impressively long lifespan and ecological dominance as an apex predator certainly seem impressive, it’s important to understand the environment in which this animal existed. The better adapted true mammals had not evolved yet, meaning that inostrancevia faced little genuine competition in its niche. So, while it was the undisputed S tier of its time, when taken out of context and put up against the later high efficiency and high intelligence pack hunters of this list, it’s clear that inostrancevia is lacking in some serious regards. Its low mobility and poor endurance would have made it an inefficient and unsuccessful predator in the age of mammals, and its low intelligence would have assured that it could not innovate its way out of this position. One could say it’s unfair to compare a stem mammal to the objectively better true mammal build, but that’s what we’re here to do, and aside from its massive size and damage output inostrancevia lacks the powerful abilities and basic efficiency that would constitute a high placement in such a competitive bracket.

I give inostrancevia the rank of high C tier.

[fundinofactoftheday]

Dinofact #7

Despite the fact that its is often grouped with dinosaurs, Dimetrodon was a synapsid which went extinct approximately 40 million years before dinosaurs existed. Additionally, as a synapsid, Dimetrodon was more closely related to mammals than to dinosaurs.

source: wikipedia