Gastornis parisiensis

Overview

Gastornis parisiensis is a giant flightless bird from early Eocene Europe. It was first described from leg bones found near present-day Paris. Its discoverer’s name and comparisons among several bones continue the story of this ancient bird.^[1]

Key facts

The name Gastornis contains that of its discoverer, Gaston Planté. In 1855, Hébert described leg bones from Meudon near Paris as a new large bird. A discovery in strata near a city became the name of an extinct bird.^[1]

Time and place

It is known from material dating to around the beginning of the Eocene, about 56 million years ago. Fossils were reported from strata at Meudon and Passy near present-day Paris, France. These records allow comparisons of early Eocene European birds.^[1]

The time range describes source context, not the complete duration of this species.

Size, form and skeleton

The first description addressed the femur and bones of the shin and ankle region. Later fossils also include the tarsometatarsus, a fused ankle-and-foot bone, and shoulder material. Small differences in the legs and shoulder offer clues for distinguishing similar giant birds.^[1]

A 2019 study comparing bird sizes estimated the body mass of Gastornis parisiensis at about 52kg. This value came from comparing several flightless birds using the same calculation method.^[4]

Habitat and reproduction

The skeleton of a large, ground-dwelling flightless bird can be compared. Shoulder and hind-limb shapes are studied alongside those of other European birds of the same period. Both the region supporting the wings and the legs supporting the body leave questions about its life.^[1]

Fossil discovery

Following the 1855 discovery at Meudon, additional fossils from Passy were reported in 1867. A 2024 study compared the shoulder and tarsometatarsus of Gastornis with Diatryma material from Germany. Even a bird known long ago can reveal different relationships through new comparisons.^[1]

References

1. Mayr et al. (2024) — Reassessment of Gastornis and Diatryma
2. Mayr (2019) — The hindlimbs of Palaeotis and relationships among Eocene birds
3. International Commission on Stratigraphy — Geological time chart
4. Crouch·Clarke (2019) — Body-size evolution in flightless birds

Research questions

How can we decide whether similar giant birds belong to the same genus? Researchers in 2024 again treated Diatryma as a separate genus based on differences in the shoulder and tarsometatarsus. Small skeletal differences allow the long history of names to be read anew.^[1]

Observation

Move your gaze from the weight-bearing hind limbs to the shoulder and wing region. Consider how bones from different regions reveal the body of this giant bird and differences from related groups.^[1]