what is the current consensus regarding diplodocids using their tails for defense?

[andrewsaurus rex]

what is the current consensus regarding diplodocids using their tails for defense?

[Halichoeres]

I don't know if there's a consensus exactly, as it seems to still be an active area of research. This paper just came out a few months ago: https://www.nature.com/articles/s41598-022-21633-2
They modeled the stresses on tails of various tissue compositions and found that they can't reach hypersonic speeds, like a bullwhip, without severe damage to the tail. That leaves a few possibilities:
• still used as a weapon, but a less devastating one
• still used as a devastating weapon, but at great cost, in really desperate situations
• used for something else, like communication

Most of which are pretty much untestable.

[stargatedalek]

I think the biggest question is why bother using them as weapons? These animals have so many much better options to defend themselves with. Why use a tail whip to cause lacerations when any predator is going to be guaranteed dead from a half decent kick?

[GojiraGuy1954]

I think the biggest question is why bother using them as weapons? These animals have so many much better options to defend themselves with. Why use a tail whip to cause lacerations when any predator is going to be guaranteed dead from a half decent kick?

In the best case scenario you don't let the predator get close enough to warrant a kick

[Sim]

I don't see "so many much better options to defend themselves with".  Also, sauropods don't seem very maneuverable or quick.  If they couldn't use their tail for defence it seems to me they would leave themselves open to attack.  Kicks would only work if the predator was within reach, and not all sauropods were big enough to leave a predator "guaranteed dead" from a kick.

[andrewsaurus rex]

I never bought into the supersonic tail whip theory.    But I can still see the tail being an effective deterrent.   Most predators like to sneak up on their prey, so that would imply that some attacks may come from the rear.  If a sauropod can use its tail to trip, or smack upside the head an approaching Allosaurus  that would seem to be a good thing to do.  It would probably hurt a lot, and let the predator know that the element of surprise is gone.

From the sauropod's perspective, why let a predator get close if you can prevent it with a simple swing of your tail?    The tip of the tail doesn't have to be the part that's used....many sauropods had very long tails so a whack from the fleshy middle part of the tail would be both forceful and much less likely to cause damage to the tail.  So, until someone proves otherwise, I prefer to think that sauropod tails were ONE of its defenses.