Wooohooo congratulations!!!!

I think the NZ Miocene holds many more surprises for the passerine fossil record. Stay tuned for more discoveries! (11/11).

These passerine lineages, as well as Aeviperditus gracilis, probably represent lineages that dispersed out of Australia during the Oligocene and Miocene, but not all survived in NZ. Aeviperditus means 'lost through the ages' - it came from a distant land but went extinct before the present. (10/11)

Aeviperditus gracilis is one piece in the puzzle to understanding NZ's ancient biodiversity. NZ is home to several endemic passerine families that arrived there early in passerine evolutionary history, but most families have not been found in the fossil record as of yet. (9/11)

Passerines from Miocene St Bathans are not well known or described, because passerine morphology is difficult to work with. The bones are mostly tiny, passerines are so diverse (~6000 living species), and key features of each group are poorly known. There's a lot more work to be done. (8/11)

We estimated the mass of A. gracilis at ~33g, which would make it the smallest of all bowerbirds. Living bowerbirds range from ~62g-292g. Our fossil bird would be about the same size as the NZ Bellbird, but with longer feet.

📸 New Zealand Bellbird. © Daniel J. Field @fieldpalaeo.bsky.social
(7/11)

Aeviperditus gracilis has a foot most similar to the avenue bowerbird clade. Bowerbirds are famous for their colourfully decorated bowers, which males of many species build to attract mates.

📸 Satin Bowerbird at his avenue bower decorated in blue. © Daniel J. Field @fieldpalaeo.bsky.social

(6/11)

A trait similarity analysis revealed it was very similar in shape to the bowerbirds (Ptilonorhynchidae) from Australia and New Guinea, which are not endemic in New Zealand or known from the NZ fossil record! (5/11)

Unfortunately it was broken at the proximal end, but the proportions are long and gracile, hence 'gracilis' in the species name. We compared it to all the endemic NZ passerine species, but nothing was similar. Scratching our heads, we looked further afield to Australian species. (4/11)

Our new fossil was described from a single 3D well preserved foot (tarsometatarsus). The bone is from a small passerine, and only measures about ~3cm in length. Micro-CT scanning meant we could study it in greater detail than under a microscope. (3/11)

Team effort from @fieldpalaeo.bsky.social @plubbe.bsky.social @nicrawlencenz.bsky.social Alex Brown and @atennyson.bsky.social between Cambridge Uni, Otago Uni and Te Papa Tongarewa.

Find the paper here www.tandfonline.com/doi/full/10.... @historicalbiology.bsky.social (🧵2/11)

And here you can find the plain-language summary🙂

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