#galloanserae

(Type specimen of Paakniwatavis grandei, from Musser and Clarke, 2024)

Meaning of name: Paakniwatavis = Paakniwat [water spirits in Shoshoni legend] bird [in Latin]; grandei = for Lance Grande [American biologist and collector of the original fossil]

Age: Eocene (Ypresian), between 51–52 million years old

Where found: Green River Formation, Wyoming, U.S.A.

How much is known: Partial skeleton of one individual including much of the skull and many limb bones.

Notes: Paakniwatavis was a waterfowl. Unlike most modern ducks and geese, Paakniwatavis lacked a broad, flattened bill. Instead, its bill more closely resembles that of an unusual group of South American waterfowl, the screamers, which have narrow, somewhat chicken-like beaks. Despite this, the describers of Paakniwatavis suggest that it was more closely related to ducks and geese than to screamers based on their phylogenetic analyses, which may indicate that the broad-billed waterfowl evolved from an ancestor similar to Paakniwatavis.

Brontornis burmeisteri was one of the largest flightless birds known to have ever existed, standing around 2.8m tall (9'2") and estimated to have weighed 400kg (~880lbs).

Known from the early and mid-Miocene of Argentina, between about 17 and 11 million years ago, it's traditionally considered to be one of the carnivorous terror birds that dominated predatory roles in South American ecosystems during the long Cenozoic isolation of the continent.

But Brontornis might not actually have been a terror bird at all – it may have instead been a giant cousin of ducks and geese.

The known fossil material is fragmentary enough that it's still hard to tell for certain, but there's some evidence that links it to the gastornithiformes, a group of huge herbivorous birds related to modern waterfowl.

If it was a gastornithiform, that would mean it represents a previously completely unknown lineage of South American giant flightless galloanserans. And, along with the gastornithids and the mihirungs, it would represent a third time that group of birds convergently evolved this sort of body plan and ecological role on entirely different continents during the Cenozoic.

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Green peafowl (Pavo muticus)

A mandarin duck in Frankfurt, Germany

Photograph: Frank Rumpenhorst/dpa/AFP via Getty Images

(Type coracoid [shoulder bone] of Tologuica vetusta [scale bar = 10 mm], from Zelenkov, 2024)

Meaning of name: vetusta = ancient [in Latin]

Age: Miocene (Burdigalian), about 16.3–16.5 million years ago

Where found: Tagay Formation, Irkutsk Oblast, Russia

How much is known: A partial left coracoid (shoulder bone).

Notes: T. vetusta was a phasianid, a group that includes chickens, partridges, and turkeys. In particular, it appears to have been closely related to Afro-Eurasian quails, such as those in the genus Coturnix. Two slightly younger species of Tologuica had previously been named from the Miocene of Mongolia, T. aurorae and T. karhui. T. vetusta was generally more similar to T. karhui anatomically, but was closer in size to the smaller T. aurorae.