@Ara Pacis
Hum,
These impacts occurred roughly 780,000 years ago during an ice age.
The extinctions that happened then, would be difficult to pin on either cause.

While it is probably true that the asteroid was the same size as the one blamed for killing off the dinosaurs 65 million years ago, the impact region was totally different.
The impacts would reflect the chemical content of the rocks around the impact craters.
The 780000 event seared a hole in the ice sheet roughly 322km by 322km that would have melted about 1% of the ice sheet and raised water levels by 60cm. The KT event happened in a shallow sea that was underlain by large sulphur containing deposits.

But of course there is the assumption that these big impacts, such as the Chicxulub impact, are a big hazard for life on the planet; the real culprit may have been volcanism...

(interestingly, new research has shown there was not a decline in dinosaur numbers before the KT event)

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`Irony` actually does mean `metal like`...