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Description

A selection of the palaeognaths known as eogruids, to scale.

Sometimes comparable features between unrelated groups can lead to confusing results. A small family of cursorial birds, known as eogruids had features in common with two distantly related modern bird groups - cranes and ostriches. Generally it was thought that they were closer to cranes in the Gruiformes (hence the name) while the slender limbs and a reduction of toes (only two were present in later species) were an adaption for running and considered convergent with ratites. Several researchers (dating back to 1951) had considered that eogruids were actually closely related to ostriches, but the consensus stood. The recent discovery of a partial skull revealed that eogruids had the 'primitive' palaeognathous palate and that that some limb material was very closely analogous to ostriches. So eogruids actually had convergent features with cranes!

Eogruids are known from Eurasian grasslands between the mid Eocene through to the Early Pliocene. Early species (Eogrus and possibly Sonogrus) were small enough to potentially be capable of flight. Later species (Ergilornis, Amphipelargus) were much larger, more cursorial and were functionally flightless.

Description

A selection of the palaeognaths known as eogruids, to scale.

Sometimes comparable features between unrelated groups can lead to confusing results. A small family of cursorial birds, known as eogruids had features in common with two distantly related modern bird groups - cranes and ostriches. Generally it was thought that they were closer to cranes in the Gruiformes (hence the name) while the slender limbs and a reduction of toes (only two were present in later species) were an adaption for running and considered convergent with ratites. Several researchers (dating back to 1951) had considered that eogruids were actually closely related to ostriches, but the consensus stood. The recent discovery of a partial skull revealed that eogruids had the 'primitive' palaeognathous palate and that that some limb material was very closely analogous to ostriches. So eogruids actually had convergent features with cranes!

Eogruids are known from Eurasian grasslands between the mid Eocene through to the Early Pliocene. Early species (Eogrus and possibly Sonogrus) were small enough to potentially be capable of flight. Later species (Ergilornis, Amphipelargus) were much larger, more cursorial and were functionally flightless.