Level 1 — Absolute Beginner
Scientists in New Zealand found a very old fossil of a goose. A fossil is a very old animal part turned to stone.
They gave the fossil a fun nickname, 'Old Mother Goose,' after an old children's rhyme.
The fossil helps scientists understand New Zealand's history. New Zealand used to have giant geese that could not fly.
The new fossil shows those giant geese are not related to this old fossil goose, like scientists once thought. The giant geese actually came from Australia much later than people believed.
- fossil
- the very old, hardened remains of a plant or animal
- nickname
- a friendly, informal name for someone or something
- rhyme
- a short poem or song with repeating sounds, often for children
- giant
- extremely large in size
- flightless
- unable to fly
- related
- connected by family or shared origin
- believed
- thought to be true
- Australia
- a large country and continent near New Zealand
Level 2 — Elementary
Scientists in New Zealand have described a newly discovered fossil goose recovered from ancient lake sediments near St Bathans in Central Otago, nicknaming it 'Old Mother Goose' after the classic nursery rhyme.
The fossil, formally named as a new species, is helping researchers rethink the history of New Zealand's unique bird life, which includes many species found nowhere else on Earth.
For decades, scientists believed New Zealand's giant flightless geese, known as Cnemiornis, had descended from an ancient lineage present in the region for more than 14 million years. The new fossil shows this ancient goose is not closely related to Cnemiornis or to its living Australian cousin, the Cape Barren goose.
Instead, the study suggests the giant flightless geese arrived from Australia only about seven million years ago, evolving rapidly into birds that stood about one meter tall and weighed up to 18 kilograms before going extinct.
- sediment
- material such as sand or mud that settles at the bottom of water over time
- species
- a group of living things that share the same characteristics and can reproduce together
- lineage
- a line of descent from an ancestor
- descended
- came down from an earlier ancestor or group
- cousin
- in biology, a species closely related through a shared ancestor
- extinct
- no longer existing as a living species
- unique
- being the only one of its kind
- recovered
- found and retrieved from a location
Level 3 — Intermediate
Researchers from the University of Otago, the Museum of New Zealand Te Papa Tongarewa, and the University of Cambridge have described a newly identified fossil goose species, informally dubbed 'Old Mother Goose,' recovered from ancient lake sediments at the renowned St Bathans fossil site in Central Otago.
Published in the journal Historical Biology, the study substantially revises long-held assumptions about the evolutionary origins of New Zealand's giant flightless geese, a genus known as Cnemiornis that went extinct following human settlement of the islands.
For roughly three decades, paleontologists had assumed Cnemiornis descended from a lineage that had inhabited New Zealand continuously for more than 14 million years. The newly described fossil, however, reveals that this ancient goose is not closely related either to Cnemiornis or to its nearest living relative, the Cape Barren goose of Australia, undermining the basis for that assumed continuity.
In its place, the study proposes a strikingly compressed timeline: the ancestors of the giant flightless geese arrived from Australia only around seven million years ago, subsequently undergoing rapid evolutionary change that produced birds standing roughly one meter tall and weighing up to 18 kilograms, a transformation that occurred far more quickly than the previous, longer-standing model had allowed.
- informally
- in a casual manner, not through official or formal means
- renowned
- well known and respected for a particular quality or achievement
- revise
- to change or update something in light of new information
- genus
- a biological grouping of closely related species
- paleontologist
- a scientist who studies fossils to understand prehistoric life
- continuity
- an unbroken and consistent existence over time
- compressed timeline
- a shortened period in which events are understood to have occurred
- transformation
- a marked and often dramatic change in form or nature
Level 4 — Advanced
A collaborative team from the University of Otago, the Museum of New Zealand Te Papa Tongarewa, and the University of Cambridge has formally described a previously unknown fossil goose, informally nicknamed 'Old Mother Goose,' recovered from the paleontologically significant lake sediments at St Bathans in Central Otago, a site that has yielded much of what is known about New Zealand's Miocene-era avifauna.
The findings, published in Historical Biology, substantially unsettle a long-standing evolutionary narrative surrounding Cnemiornis, the genus of giant flightless geese that persisted in New Zealand until shortly after human arrival, by demonstrating that the newly described species shares no close phylogenetic relationship with either Cnemiornis or its extant Australian relative, the Cape Barren goose.
This finding directly contradicts a model that had held sway for roughly three decades, under which Cnemiornis was presumed to represent an unbroken lineage stretching back more than 14 million years within New Zealand, a continuity that had itself served as something of a touchstone for broader theories about the deep antiquity of the archipelago's endemic avifauna.
In its place, the authors advance a markedly more compressed evolutionary timeline, positing that the ancestors of the giant flightless geese colonized New Zealand from Australia only around seven million years ago before undergoing an accelerated period of morphological change culminating in a flightless giant standing roughly one meter tall and weighing up to 18 kilograms, a pace of evolutionary transformation that, if correct, would rank among the more rapid documented instances of insular gigantism in avian evolutionary history.
- avifauna
- the bird species of a particular region or time period
- phylogenetic
- relating to the evolutionary relationships and history between species
- extant
- still existing, not extinct
- touchstone
- a standard or reference point by which something is judged
- endemic
- native to and found only in a particular geographic area
- posit
- to put forward an idea or theory as a basis for argument
- morphological
- relating to the form and structure of an organism
- insular gigantism
- an evolutionary pattern where species on islands evolve unusually large body size
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