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How Do We Know This?
Careful study of fossil bone or tooth anatomy yields much
exact information about placement and strength of muscles, tendons, ligaments, nerves,
and blood vessels. In rare cases, skin and hair impressions or actual skin or hair remains.
Body weight is more difficult to gauge because fat leaves no impression on the skeleton.
|Attribute||Teratornis merriami||Ailornis incredibilis||Argentavis magnificens|
|Estimated Body Weight
||13.7 kg (30.2 lb) (Campbell & Tonni 1983)
Slightly heavier than living California Condor.
|23 kg (50 lb)
||70 kg (154 lb); 7 times heavier than California Condor (Chatterjee et al 2007)
||3.5-4 m (11.5-13.1 ft)
||5.0-5.5 m (16.4-18 ft)
||6-8 m (19.7-26.3 ft)
- Large soaring predatory birds with stout legs, long toes, with the last digits moderately curved and blunt (not used for holding prey as in hawks or eagles).
- Pelvis resembles a stork's; they were adept walkers on the ground, but not good runners. (Campbell & Tonni 1983)
Other Physical and Physiological Characteristics
- Wing bones have features of condors and also pelicans and Bald Eagles (Campbell & Tonni 1983) (Hertel 1995).
- Sutures between some skull bones are not tightly fused; this may help teratorns swallow large and struggling prey (Campbell & Tonni 1981).
- This is one reason paleontologists do not think they had scavenging habits.
- A sharp hooked bill known for T. merriami; skull of Argentavis not known.
Chatterjee et al (2007)
Campbell & Tonni (1983)
Campbell et al (1999)
SDZWA Library Links
Fact Sheet Index
Fact sheet index, San Diego Zoo Wildlife Alliance Library
Home page, San Diego Zoo Wildlife Alliance Library
Email the librarians at firstname.lastname@example.org