This is the only episode in the first two seasons in which Rick Marshall doesn't make an appearance. Spencer Milligan had taken time off to guest-star in The Dawson Marker (1976), Barbary Coast's final episode due to the series being cancelled.
The narrative demands Big Alice's egg be difficult to steal and a normal human would only be knee high to an adult allosaurus so you might expect enormous eggs. Surprisingly, the largest dinosaur eggs ever found are in the 1 foot long range, barely larger than ostrich eggs. Allosaurus eggs were about fist sized (well, for a fairly large fist).