Can you change the tooltip of the buttons at the top right of the observation detail page to indicate whether the arrow is navigating to newer or older observations?
On iNat, the right pointing arrow goes to newer content, but on some sites similar buttons actually go to older content.
Gmail - left is newer, right is older
iNat observation detail - left is older, right is newer
Default Identify pagination (and arrows on pop-up modal) - left is newer, right is older
Alternatively on the observation detail page they could be up/down instead to indicate the newest observations are at the “top of the stack”.
Outlook - left/up is newer, right/down is older
I personally rarely use these buttons on iNat, but when I do, I never know which one to press to view newer or older observations.