So if I understood this article correctly, the key conclusion is this - metamorphosis was not the condition for moving onto land?

The traditional picture was:

Tetrapods could leave water because they first evolved a tadpole-like larval stage and then metamorphosed.

The new interpretation suggested by these fossils is closer to:

Tetrapods gradually adapted to land over evolutionary time, and they probably did not need a frog-like metamorphosis to do it.

In other words, metamorphosis was probably not a prerequisite for terrestrial life. Instead, the transition from water to land appears to have been a long, gradual evolutionary process affecting the whole life cycle, rather than depending on a distinct larval stage.

Analogy of two possible scenarios:

Old model

• Young live in water.
• Undergo a major developmental transition.
• Adults become adapted to life on land.

New model

• Young and adults share the same basic body plan.
• Land adaptations accumulate gradually over millions of years (generations).

So the narrative shifts from:

Metamorphosis enabled the move onto land

to:

The move onto land happened gradually, and amphibian-style metamorphosis likely evolved later as a specialized adaptation.

https://www.404media.co/a-new-fossil-discovery-just-rewrote-150-years-of-evolutionary-theory

#Biology #Evolutionary #EvolutionaryBiology #Fossil #Discovery #Metamorphosis #Tetrapods #Science

Illustration by Maria Sibylla Merian, from Metamorphosis Insectorum Surinamensium (1705).

Source: Smithsonian Libraries and Archives / Biodiversity Heritage Library

Available to buy as a print.

https://pdimagearchive.org/images/331031ee-5a8e-48ee-b037-1dfe2ac3dda2

#metamorphosis #insects #moths #caterpillars #botanical #butterflies #flora #flowers #berries #leaves #plants #art #publicdomain

Nazli Abbaspour (b.1975)

https://palianshow.wordpress.com/2026/05/29/nazli-abbaspour/