Rather than weigh directly into the rather heated debate delow, I thought I would post some basic info about these topics and the understanding of 99.9% of Geologists on the subject:-

Expanding Earth:-
1) GPS and other satellite measurements show that the Earth is not expanding now with an accuracy 100 times greater than needed to detect the supposed expansion caused by the opening of the Atlantic and Pacific oceans.

2) GPS and other long-term measurements such as VLBI show that subduction exactly balances crustal expansion at ridges.
The understanding of Plate Tectonics did indeed emerge via concepts of Expanding Earth in contrast to the fixist Earth that was formerly beleived. However, in the mid-70's even the recalcitrant Americans were persuaded of the simplicity and merit of the plate tectonic process.

3) Today, an integrated study of Mantle dynamics, plate motions, earthquakes, volcanoes, mineral deposits and biological dispersion over geologic time points to ongoing plate tectonics for at least the last couple of billion years.

4) None of the other planets or moons in our Solar System show signs of "expansion" either, especially our Moon which has been cratered and dead for 3.6 Billion Years. (Indeed, if you look closely at Mercury, Mars, and the Moon they all show wrinkles due to planetary cooling and shrinking over geologic time - by about 0.3%, but still detectable).

5) As for animals "tending to decrease" over time, this must come from someone who has never compared an Elephant with their pig-sized ancestors, or studied the prolific giant mamalian faunas that developed in the midlle Tertiary from rodent-sized precursors. Blue whales used to be the size of dogs...

6) I could go on at length, but there is abundant incontrovertible evidence that neither Expanding Earth nor Shrinking Animals are tenable hypotheses to an intelligent and properly-informed person.