OK ; maybe I'm a bit too close to the data to read the article without bringing knowledge from other areas to bear. The sequence as best we can determine so far is :
(1) T0 : Deccan Traps start erupting (along with the Reunion volcanics, probably, from the palaeogeography)
(2) +170,000 years : Chicxulub impact.
(3) + short period, maybe up to ~60,000 years : Dinosaurs and many other groups start going extinct.
Although, given the imprecision of the timing for large, long-lived animals compared to short-lived ones, it is possible that (2) and (3) are more like :
(2) as above;
(2a) +months to 1 year : direct impact damage, fire and starvation do for large dinosaurs ; small dinosaurs and other meso-fauna survive ; dung beetles can't find enough fresh poo piles ;
(2b) +10 years : ocean pH has dropped by 3 units (1000x more acid) ; major extinctions of marine microflora ; seeds from previous flora are germinating, but with an absence of large herbivores, there are drastic ecological changes (compare what happened to the US/Canadian steppes when the bison was almost extinguished).
(2c) +20 years : ocean pH rebounds by 1 unit, but many large marine life forms starving to death (or reproductive inability - same thing).
[...] continuing series of sequels for millennia.
Disentangling such a sequence will be a real challenge, given that in deep marine sediments (our most stable environment, where you're likely to get the most consistent records without storms taking out the critical metre of sediment), it's perfectly possible to have bioturbation (worm burrows) stir things up through a metre of sediment thickness - a good million years worth. Of course, we could look at a K-Pg analogue of the Euxine Sea (a.k.a. "Black Sea" ; the archetype euxinic basin where the bottom waters are nearly sterilised by hydrogen sulphide because of restricted water circulation) if we (1) wanted to look at only planktonic organisms and (2) we could find such a basin (any suggestions? I don't know of one off-hand, though I've not studied the question. When I'm working next year in the Black Sea, I'll maybe do a literature search).