Did animals die before the Fall? If yes, can dinos be very, very old?
Animal Death could be Consequence of the Fall (Patristic support and scientific consideration)
Carnivores in Eden?
I previously wrote an article without supporting vegetarian lions before the fall. This is because St Thomas and St Augustine seemed not to support this and St Basil was not clear about it in Hexaëmeron, it depends on whether he used "creation of fifth day" and "creation of sixth day" as moral examples in their state now after the fall or in their state previous to the fall. Now I have however written a question to one better patrologist than I, one Professor Benno Zuiddam.* I will quote his answer:
My pleasure, although many fathers don’t deal with this issue specifically, but rather implicitly, St Irenaeus is you best bet as a Western father: Against Heresies, Book V, Chapter 33.4.
Also have a look at St. John Damascene, St. Gregory the Sinaite, St Simeon, etc. Even St. John Chrysostom teaches that: “Just as the creature became corruptible when your body became corruptible, so also when your body will be incorrupt, the creature also will follow after it and become corresponding to it.” (Homilies on Romans, XIV, 5), similarly Macarius Magnes (Homily 11).
Thus, there is Patristic support for animals not being eaten before the fall.
Now, here is the scientific consideration: if there is observed scientific truth in microevolution, and if species with degraded eyes are supposed to have had originally functional eyes, before they came to live in caves with complete darkness, then the original capacity of wolves or lions to eat grass may have degraded as well.
St Basil the Great
and St Elisaeus the Prophet
*http://www.bennozuiddam.com/ (Not advised for the not well grounded Catholics, since it contains Protestant material, but if you are a priest or have a priest's permission, you will find a courteous man with knowledge of Church Fathers and not just Reformers - though one obvious problem is that he is prepared to compare the cultus dulie of saints with the cultus latrie of dead emperors, heros or pagan gods that never lived or [as with sun and stars, angels serving God] never wanted such cultus - He gives following correction to this caveat: "Gezonde heiligenvereering brengt nader aan God is on my website, as are Newman, a Kempis and More, so Protestants should start publishing caveats for my website as well!").