#multituberculate earth

[harpagornis]

Tupanbaatar brasilensis

Tupanbaatar brasilensis, a Miocene species from Brazil. A notoptilodontoidean, it showcases the transformation of the second premolar into a caniform saber tooth. Like in other cimolodonts these fangs are grown throught the animal's life much like the main plaugiaulacoid premolar. For Multituberculate Earth, by hellagator

[harpagornis]

Gondwanatheria: World Domination

(As with all animal pages so far, this only goes so far into the Miocene… for now) Fusuamys, from the early Paleocene of Bolivia. By pale.re

Manik xtabay from the Oligocene of Colorado. Here speculatively using tools much like modern cows. By astraplatina

[harpagornis]

New animal for Multituberculate Earth: https://multituberculateearth.wordpress.com/2022/04/03/mammals-at-sea/

[harpagornis]

South American multies!

A recent study describes a tooth from a South American multituberculate. Previous multituberculate fossils have been found in Australia (Corriebaatar), India (Indobaatar) and Madagascar (a femur from the Maevarano Formation), with this fossil not only proving their presence in South America but also directly establishing a clade previously thought only to have occured in the northern hemisphere: Ptilodontoidea.

As to how this affects my lovely spec evo project Multituberculate Earth? Not much, as I already have a clade of gondwannan ptilodontoidean multies, and it’s nice to have science reinforce my work. The study does suggest that ptilodontoideans likely became extinct in the southern hemisphere during the KT event, so the Paleocene origin I gave the group kinda goes both ways.

Overall a good discovery that highlights the diversity of this group of mammals.

[harpagornis]

Plummobaatar diathagoia, a new submission for Multituberculate Earth: https://multituberculateearth.wordpress.com/2024/07/30/example-site-messel-pit/

[harpagornis]

New Multituberculate Earth content: https://multituberculateearth.wordpress.com/2022/03/29/kogaionidae-old-dogs-do-learn-new-tricks/

[harpagornis]

Illyriolestes piscimimus, a new critter for Multituberculate Earth: https://multituberculateearth.wordpress.com/2022/04/03/mammals-at-sea/

[harpagornis]

Multituberculate Earth: Messel Pit

Messelboffius atraxa, a red-kangaroo sized hopper from the Eocene of Europe, coupled with its muscular anatomy. By Dr Spooky.

The Messel Pit is a world renowed (being even a UNESCO heritage site) fossil site in Germany, dating to the Lutetian stage of the Eocene. It represents a lake environment associated with a volcano, the latter likely providing toxic gases that routinely killed the local fauna (such events have been compared to our timeline’s Lake Nyos incidents). The lake likewise had an anoxic layer preventing normal decomposition by bacteria; as a result, animals that fell into the lake’s deeper regions became exceptionally well preserved. Soft tissues from hair to organs are known, all captured within thin limestome slabs.

The climate in the region was tropical; in this timeline, perhaps even hotter thanks to an extended thermal maximum. Tropical rainforests covered what was once an island continent, as Europe was isolated from the other landmasses. This allowed it to develop an unique fauna with elements from both Laurasia and Gondwanna.

Taeniolabidids were the largest land mammals in the continent, though european forms were mostly island dwarfs; the local Gauliolabis messelnienses, the very largest land mammal in the site, rarely surpassed 120 kg. It was a semiaquatic herbivore, though more closely related to north american giants than to other aquatic forms. The second largest mammal was Messelboffius atraxa, a boffiid, about as large as a red kangaroo at 47 kg, and similarly a hopper much like most of its relatives.

No, the largest land animal was not a mammal but rather the famous flightless bird Gastornis. Europe, much like in our timeline, had birds as the largest land animals, making it rather similar to Madagascar in our timeline’s Pleistocene, being another island continent ruled by giant birds. Terrestrial crocodilians like Bergisuchus and Boverisuchus were the apex predators on land, with more familiar forms ruling the waters. It was truly a reminder of the age of the dinosaurs.

Still, some mammals packed a punch. Celtoptilodus giganteus was a bobcat sized ptilodontoid and the largest mammalian carnivore in the region, followed closely by the symmetrodont Taranomamus horridus, a more robust and badger like animal. Ptilodontoids and symmetrodonts occupied the main carnivorous and omnivorous niches among mammals, and though several species were small (particularly symmetrodonts) their menagerie was vast. Another common group of omnivores were the eucosmodontids; though many forms were terrestrial mouse to cat sized species, the Messel Pit preserves two genera of flyers: Khusuurbaatar, with wings supported by its styliform, and Plummobaatar gaulica, with wings composed of feather-like hairs.

Khusuurbaatar elegans by Dave García. One of various flying euscosmodontid lineages, this one lasted across the Eocene, with fossils found in Asia, Europe, North America, Australia and Antarctica. It was a genus of fast aerial insectivores, this species being the largest known with a wingspan of 60 centimeters.

Another flyer was the ptilodontoid Pteroectypodus falco, which also occured in contemporary sites in North America. This diversity of flying mammals rivals our timeline’s bat diversity, of which several species are known from the Messel Pit.

Pteroectypodus falco by Diego Ortega Anatol.

Among herbivorous mammals, the most common were the gondwanathere feruglitheriids, which likely arrived to Europe from North America (and in turn from South America) in the Paleocene. They and the boffiids compromised the main herbivorous guilds: the ferugliotheriids ranged from mouse sized to 50 kilo large forms, from burrowers to sloth-like tree climbers, while boffiids were more typical hoppers, ranging from jerboa sized to the aforementioned Messelboffius atraxa.

Microcosmodontids were smaller in Europe than in other land masses, the largest being the mole-sized burrower Velesotherium occidentalis. The eucosmodontid Thylacolutra messeliensis occupied an aquatic forager niche akin to an otter, while the ptilodontoid Amaxillodens plagiaulacoides lost its upper dentition, relying on its plagiaulacoid teeth and robust claws to open termite nests.

The unique fauna of the Messel Pit is a slice in time of when Europe was allowed to develop its fauna in isolation. With the Grand Coupure, climatic changes and competition from arrivals from Asia ended this strange world. But for almost twenty million years, the fauna of Europe thrived in their tropical island paradise.