From James Beals:

Re: One more terror for ancient ocean fish: monster ducks (Sept. 26): I find it amazing that you can decide the length and width of an animal simply by studying the skull. How do you even disqualify that this animal was terrestrial. Tell me what airplane has only a 15 foot wing span. If you meant a model airplane then you should have indicated that.

James Beals

(Editors' note: According to the nonprofit website aerospaceweb.org, the smallest functioning, piloted airplane in history was “called the Stits Junior... [it] was around 11 ft (3.4 m) in length and had a wingspan that varied between 8.8 and 9.3 ft (2.7 to 2.8 m) over the course of three different modifications.”)