Ancestral state reconstructions show that the pouch has been gained and lost multiple times during marsupial evolution, although the ancestral marsupial condition remains uncertain, but most likely corresponding to pouch absence.

We used phylogenetic comparative methods to investigate the relationship between pouch presence, body mass and litter size across 195 species. Our results show that the probability of pouch presence increases with body mass and decreases with litter size.

When we think of marsupials, the first thing that comes to mind is the presence of a pouch. But despite this striking anatomical feature, not all marsupials have it. What factors determine its presence or absence?

In the case of N. fissuratus, the perpetuator was likely sparassodont metatherians, one of the few compelling evidence of this kind of predator-prey in the South American fossil record.

These large punctures on the symphiseal part of the jaws are consistent with predation by metatherians, as practiced by living didelphids

We describe a new ichnospecies, Nihilichnus fissuratus isp. nov., which are constituted of symmetrical marks on the mandibles, likely from antagonistic teeth.

I'll make a presentation on #SVP2025 about what may be the first indications of predation by sparassodonts, an extinct group of South American metatherian predators.

I will present today about the geographic and sexual skull variation in yellow-throated martens (subgenus Charronia) at the "General Morphology and Morphological Evolution 1" session of #ICVM2025

I will be talking about cranial evolution in martens, wolverines, and tayras tomorrow at the "Macroevolução 2" session of the I Congresso Brasileiro de Biologia Evolutiva, in Curitiba, Brazil! #SBBE #SBBE24 #biologiaevolutiva