A tiny short-legged bird from the early Oligocene of Poland

• Main Authors: Bochenski Zbigniew M., Tomek Teresa, Swidnicka Ewa
• Format: Article
• Language: English
• Published: Earth Science Institute, Slovak Academy of Sciences, Slovakia 2016-10-01
• Series: Geologica Carpathica
• Subjects: Fossil birds; Menilite shales; Carpathian flysch; Palaeogene
• Online Access: http://www.degruyter.com/view/j/geoca.2016.67.issue-5/geoca-2016-0029/geoca-2016-0029.xml?format=INT

We describe an articulated partial leg of an Oligocene bird. It is one of the smallest avian fossils ever recorded. Its slender and exceptionally short tarsometatarsus, hallux as long as the tarsometatarsus and stout moderately curved claws agree with stem-group Apodidae (swifts), stem-group Trochilidae (hummingbirds), and stem-group Upupidae/Phoeniculidae (hoopoes/woodhoopoes). Unfortunately, due to the poor preservation of the specimen its more precise affinities remain unresolved. The specimen differs in many details from all other tiny Palaeogene birds and therefore most probably it represents a new taxon but it is too fragmentary to describe it. It is just the twelfth avian fossil from the Oligocene marine deposits of the Outer Carpathians and Central Palaeogene Basin — a huge area that covers south-eastern Poland, north-eastern Czech Republic and northern Slovakia — and therefore it adds to our very limited knowledge on the avifauna of that region. The remains of land birds from Jamna Dolna and other sites of the region can be attributed to the general sea level fall at that time, which led to limitation of the connection with the open ocean and resulted in many shallow shoals, temporary islands and exposed dry land areas along the coast.