Miniature, insect-eating ancestor of dinosaurs unearthed in Madagascar

[muriel_volestrangler]

The Kongonaphon kely measured about 40cm (16in) long and stood 10 cm (4in) tall at the hip, scientists said on Monday. It inhabited a floodplain region of what is now south-western Madagascar during the Triassic period about 237m years ago.
...
It was a member of a group called Ornithodira spanning the evolutionary lineage that led to dinosaurs and pterosaurs – large flying reptiles – part of a larger assemblage called archosaurs that also included the crocodilian lineage.
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Dinosaurs and pterosaurs first appeared roughly 230m years ago. The early dinosaur Herrerasaurus was about 6 metres (20ft) long. The early pterosaur Eudimorphodon was pigeon-sized. Both groups eventually achieved gigantic proportions. The pterosaur Quetzalcoatlus had a wingspan of about 10.5 metres, akin to an F-16 fighter. The dinosaur Argentinosaurus reached about 35-metres long.
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“However, it fits the broader pattern that we observe at this time. There was a sustained trend towards smaller adult body sizes in the early history of this lineage. This is based not only on Kongonaphon, but on a series of small-bodied reptiles near the common ancestry of the dinosaur and pterosaur lineages.”

https://www.theguardian.com/science/2020/jul/07/miniature-insect-eating-dinosaur-ancestor-unearthed-in-madagascar

And it may show the tendency to body filaments that later became feathers was useful in these tiny ancestors for retaining heat:

Kongonaphon is not the first small fossil animal known near the root of the ornithodiran family tree but, previously, such specimens were considered isolated exceptions.

In general, scientists thought body size remained similar among the first archosaurs - the larger reptile group that includes birds, crocodilians, non-avian dinosaurs, and pterosaurs - and the earliest ornithodirans.
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The work also suggests that fuzz over the skin, ranging from simple filaments to feathers, known on both the dinosaur and pterosaur sides of the ornithodiran tree, may have originated for regulating body temperature in this small-bodied ancestor.

That's because heat retention in small bodies is difficult, and the mid-late Triassic Period, when the animal lived, was a time of climatic extremes. Researchers think there were sharp shifts in temperature between hot days and cold nights.

https://www.bbc.co.uk/news/science-environment-53319635

Paper singificance and abstract:

Reptiles of the Mesozoic Era are known for their remarkable size: dinosaurs include the largest known land animals, and their relatives, the pterosaurs, include the largest creatures to ever fly. The origins of these groups are poorly understood, however. Here, we present a species (Kongonaphon kely) from the Triassic of Madagascar close to the ancestry of dinosaurs and pterosaurs, providing insight into the early evolution of those groups. Kongonaphon is a surprisingly small animal (estimated height, ?10 cm). Analysis of ancestral body size indicates that there was a pronounced miniaturization event near the common ancestor of dinosaurs and pterosaurs. Tiny ancestral body size may help explain the origins of flight in pterosaurs and fuzzy integument in both groups.

Early members of the dinosaur–pterosaur clade Ornithodira are very rare in the fossil record, obscuring our understanding of the origins of this important group. Here, we describe an early ornithodiran (Kongonaphon kely gen. et sp. nov.) from the Mid-to-Upper Triassic of Madagascar that represents one of the smallest nonavian ornithodirans. Although dinosaurs and gigantism are practically synonymous, an analysis of body size evolution in dinosaurs and other archosaurs in the context of this taxon and related forms demonstrates that the earliest-diverging members of the group may have been smaller than previously thought, and that a profound miniaturization event occurred near the base of the avian stem lineage. In phylogenetic analysis, Kongonaphon is recovered as a member of the Triassic ornithodiran clade Lagerpetidae, expanding the range of this group into Africa and providing data on the craniodental morphology of lagerpetids. The conical teeth of Kongonaphon exhibit pitted microwear consistent with a diet of hard-shelled insects, indicating a shift in trophic ecology to insectivory associated with diminutive body size. Small ancestral body size suggests that the extreme rarity of early ornithodirans in the fossil record owes more to taphonomic artifact than true reflection of the group’s evolutionary history.

https://www.pnas.org/content/early/2020/07/01/1916631117

[fleur-de-lisa]

1. Cool!

[marble falls]

2. Proto-Chihuahua.

[Baked Potato]

3. That little dude could tear up a living room!