First appearance in the series of Mía Maestro as Nadia Santos, Sydney's sister. Maestro would become a series regular in the following season.
The facility used as Novgorod 21 is the same filming location in 24 (2001) Season 4 Episode 6 that the Marines rescue Jack (Kiefer Sutherland), James Heller (William Devane) and Audrey Heller (Kim Raver) from.
Last episode to be directed by Jack Bender for the series, before taking on J.J. Abrams' another series Lost (2004), in which he served as an executive producer and leading director.
While Sydney may be referring to a specific Mamenchisaurus specimen, some Mamenchisaurus species are estimated to have necks as long as 49+ feet (15 meters), not merely 36 feet. Also, the theory that these sauropods had a second brain in the lower spinal cord near the hips has fallen out of favor.