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Lack of fungus did not cause Coal Age + fish evolution + Kunbarrasaurus skull + more

Ben Creisler

Some non-dino stuff that may be of interest:

Matthew P. Nelsen, William A. DiMichele, Shanan E. Peters, and C.
Kevin Boyce (2016)
Delayed fungal evolution did not cause the Paleozoic peak in coal production.
Proceedings of the National Academy of Sciences (advance online publication)
doi: 10.1073/pnas.1517943113


The Carboniferous−Permian marks the greatest coal-forming interval in
Earth’s history, contributing to glaciation and uniquely high oxygen
concentrations at the time and fueling the modern Industrial
Revolution. This peak in coal deposition is frequently attributed to
an evolutionary lag between plant synthesis of the recalcitrant
biopolymer lignin and fungal capacities for lignin degradation,
resulting in massive accumulation of plant debris. Here, we
demonstrate that lignin was of secondary importance in many floras and
that shifts in lignin abundance had no obvious impact on coal
formation. Evidence for lignin degradation—including fungal—was
ubiquitous, and absence of lignin decay would have profoundly
disrupted the carbon cycle. Instead, coal accumulation patterns
implicate a unique combination of climate and tectonics during Pangea


Organic carbon burial plays a critical role in Earth systems,
influencing atmospheric O2 and CO2 concentrations and, thereby,
climate. The Carboniferous Period of the Paleozoic is so named for
massive, widespread coal deposits. A widely accepted explanation for
this peak in coal production is a temporal lag between the evolution
of abundant lignin production in woody plants and the subsequent
evolution of lignin-degrading Agaricomycetes fungi, resulting in a
period when vast amounts of lignin-rich plant material accumulated.
Here, we reject this evolutionary lag hypothesis, based on assessment
of phylogenomic, geochemical, paleontological, and stratigraphic
evidence. Lignin-degrading Agaricomycetes may have been present before
the Carboniferous, and lignin degradation was likely never restricted
to them and their class II peroxidases, because lignin modification is
known to occur via other enzymatic mechanisms in other fungal and
bacterial lineages. Furthermore, a large proportion of Carboniferous
coal horizons are dominated by unlignified lycopsid periderm with
equivalent coal accumulation rates continuing through several
transitions between floral dominance by lignin-poor lycopsids and
lignin-rich tree ferns and seed plants. Thus, biochemical composition
had little relevance to coal accumulation. Throughout the fossil
record, evidence of decay is pervasive in all organic matter exposed
subaerially during deposition, and high coal accumulation rates have
continued to the present wherever environmental conditions permit.
Rather than a consequence of a temporal decoupling of evolutionary
innovations between fungi and plants, Paleozoic coal abundance was
likely the result of a unique combination of everwet tropical
conditions and extensive depositional systems during the assembly of



But this recent article tells the traditional version:



Early fish evolution



And dino stuff:

Reconstructing the head of Kunbarrasaurus



Jaw Mechanics in Ornithischian Dinosaurs



More on research with T-Rex "Tristan" in Berlin (in German)