Published on September 15th, 2019 | by Liz Martin-Silverstone


Episode 103: Terror birds

Terror birds, or phorusrhacids as they are known scientifically, are a group of large, flightless birds that lived during the Cenozoic, and truly lived up to their name. Known for their large, powerful skulls, and enormous beaks, these birds are unlike the flightless birds we have alive today. Despite their strange appearance and unique morphology, terror birds aren’t well known in popular culture. What were they doing? How big did they get? What did they eat?

In this episode, we talk to a leading terror bird expert, Dr Federico “Dino” Degrange from the Centro de Investigaciones en Ciencias de la Tierra (CICTERRA) in Córdoba, Argentina to get answers to these questions. We discuss some of his recent research, and what we know (and don’t know) about phorusrhacids today.

Federico “Dino” Degrange on the WitmerLab working on the sensory system of phorusrhacids.
Dino in the Mio-Pliocene of Catamarca province, NW of Argentina, looking for phorusrhacids.
Skull of Psilopterus lemoinei, a small phorusrhacid from the santacrucian of Argentina. The material is housed in the AMNH museum.
Skull of Psilopterus bachamnni, the smallest phorusrhacid ever found. This species cohabitated with Psilopterus lemoinei, although it was smaller (4 kg).
Kelenken guillermoi, one of the most largest terror birds ever found. Its skull is, also, the largest bird skull ever found!!
Llallawavis scagliai, the most complete skeleton of a phorusrhacid ever found. Photo courtesy of M. Taglioretti.
Andalgalornis steulleti, a terror bird from the Mio-Pliocene of Catamarca province, NW of Argentina. Based on this species, Larry Marshall created the term “terror birds” in 1978 for these birds. Photo courtesy of L. Witmer.
Inner ear morphology of Cariamiformes, the group of birds that includes phorusrhacids and seriemas. Taken from Degrange et al. (2015) JVP.
Phylogenetic hypothesis of phorusrhacids. Taken from Degrange et al. (2015) JVP
Phorusrhacids are the only truly akinetic Neornithes (i.e., they have lost the capability of moving the beak in relation the the braincase). See in the figure the palatal zones, the craniofacial hinge and the contact between the lacrimal bone and the jugal bar are completely ankylosed (fused). In modern birds, these are not fused and allow for movement of the beak. Taken from Degrange et al. (2010) PLoS One

Photos from Dino Degrange unless stated otherwise.

Tags: , , , , , ,

Back to Top ↑