LRT mammal clade with niches indicated
With over 600 extinct and extant trait-tested taxa,
the mammal subset of the large reptile tree (LRT 2336 taxa, subset Fig 1) seems to be in pretty good shape now (after 330 daily revisions). To test this subset I applied niche colors (knowing some, guessing others).
Click here to enlarge this mammal subset with colored niches.
Figure 1. Subset of the LRT focusing on mammals. Color bars added according to niche.
Figure 1. Subset of the LRT focusing on mammals. Color bars added according to niche. Figure 1. Apologies for the tiny type. Inevitable given column restrictions. Click to enlarge.
The mammal subset is likely not perfect.
I’d like to not interrupt early arboreal taxa (like Labidolemur) from later arboreal taxa (like Microcebus) with terrestrial hedgehogs, shrews and moonrats. We’ll see how that goes. Did they relearn old skills? Or do we lack arboreal pre-moonrats and hedgehogs in the fossil record?
Time and new taxa will tell.
I note several gliding marsupials
at the origin of that clade. These include several gliding multituberculates by convergence all evolving from arboreal precursors, often quite tiny. All avoided terrestrial theropods, but got to know sauropod snouts.
On the other end of the niche spectrum
the marsupial moles in the Jurassic gave rise to extant marsupial moles and two convergent clades of extant and extinct placental moles. Tiny Dianoconodon and the even smaller (it’s a juvenile with unerupted teeth) Hadrocodium are basal. One can hypothesize a terrestrial habitat for these two climbing through leaf litter, then gradually graduating to digging burrows. Burrows go back to monotremes (like Ornithorhynchus) and the earliest cynodonts, like Thrinaxodon. Of course a wide range of other later, larger placentals also dug burrows, culminating with massive Megatherium and mechanically aided Homo sapiens.
I am not aware
of another trait-based mammal cladogram with 600+ taxa. If you know of one, please send a citation so I can promote it here.
Source: https://pterosaurheresies.wordpress.com/2025/03/09/lrt-mammal-clade-with-niches-indicated/
