Tyloses are protoplasmic swellings of parenchyma cells into the lumen adjacent conducting cells. They develop as part heartwood formation process, or in response to embolism pathogen infection. Here, we report oldest fossil evidence date tylosis that occurs permineralized wood (pro)gymnosperm Dameria hueberi from Tournaisian (lower Mississippian, ca. 350 Ma) Australia. Different developmental s...

Varanids are the only non-avian sauropsids that known to approach warm-blooded mammals in stamina. Furthermore, a much higher maximum metabolic rate (MMR) gives endotherms (including birds) stamina than crocodiles, turtles, and non-varanid lepidosaurs. This has led researchers hypothesize mammalian endothermy evolved as second step after acquisition of elevated MMR non-mammalian therapsids from...

The Earn Group of central Yukon records the transition from a passive to an active margin along western Laurentia in Late Devonian. Fine-grained clastic rocks and chert lower contain late Early Middle Devonian fossils were deposited offshelf environment. upper comprises mixture sandstone conglomerate, fine-grained siliciclastic rocks, widespread crystal lithic tuff. Zircons this succession are ...