These were the unlikely survivors after dinosaurs went extinct

When an asteroid hit the Earth 66 million years ago, it unleashed a violent force millions of times more massive than...

Posted: May 24, 2018 10:37 PM
Updated: May 24, 2018 10:37 PM

When an asteroid hit the Earth 66 million years ago, it unleashed a violent force millions of times more massive than an atomic bomb. Known as the Cretaceous-Paleogene fifth mass extinction event, it wiped out three-quarters of all plant and animal life on Earth -- including the dinosaurs.

A new study suggests that the impact also decimated Earth's forests, leading to the extinction of all the birds that lived in trees. But in a twist, the plucky survivors in the fiery aftermath proved to be ferns and hardy, ground-dwelling birds.

Ferns and ground-dwelling birds survived the fifth mass extinction, according to a new study

All of today's birds descended from the survivors

The study was published Thursday in the journal Current Biology.

Scientists also refer to the event as the K-Pg Chicxulub impact because it created the Chicxulub crater in what's now Mexico. During the initial impact, shock waves flattened trees in massive waves within a radius of nearly 1,000 miles. But what followed was probably even worse for the initial survivors of this apocalyptic event.

The intense heat generated by the impact would have sparked global wildfires, ravaging what was left of the forests. Vapor, rich in sulfates, triggered acid rain. Soot clogged the atmosphere, which put a damper on the photosynthetic activity that plants needed to survive or grow back. This lasted years, which kept the global climate from cooling.

Not only did the forest canopies collapse, they wouldn't be able to regrow. Any birds that roosted or perched in trees would've been homeless. The chance of surviving the asteroid was already slim for tree-dwelling birds; eliminating their habitat ensured extinction.

Researchers from the United States, England and Sweden studied the fossil record from North America to New Zealand, looking closely at charcoal remains of trees, fossilized pollen and fern spores, and bird fossils. The combination of samples provided a bigger picture of what the world was like during the aftermath of the impact.

"To me, it's really exciting to see that combining insights from the bird fossil record and the plant fossil record can allow us to piece together a major macroevolutionary story that took place over 66 million years ago," Daniel Field, lead study author and an evolutionary paleontologist at the University of Bath's Milner Centre for Evolution, wrote in an email. "It speaks to the power of collaborative science, and the importance of the fossil record for understanding the life in the modern world."

A perilous life on the ground

The ground-dwelling birds that survived would not have had an easy existence. It's likely that smaller ground-dwelling birds experienced a catastrophic loss. They probably lived off the hardiest grains and seeds that endured the impact, as well as insects. Many small-bodied birds today eat insects, and this trait can be traced to the surviving birds 66 million years ago.

"My guess is that any surviving birds would have been fairly skinny for a few years in the immediate aftermath of the asteroid impact," Field said.

Their fossils reveal that the ground-dwelling birds had long, sturdy legs, like those of a kiwi or an emu, nothing like the delicate legs of perching birds.

They can be compared to today's tinamous, small-bodied, flying and ground-dwelling relatives of ostriches and emus that live in Central and South America. Being small, flying and living on the ground were probably all features that would have favored survival across the mass extinction event, Field said.

But the ground-dwelling birds that survived carried a lasting legacy beyond the tinamous.

"Today, birds are the most diverse and globally widespread group of terrestrial vertebrate animals -- there are nearly 11,000 living species," Field said in a statement. "Only a handful of ancestral bird lineages succeeded in surviving the mass extinction event 66 million years ago, and all of today's amazing living bird diversity can be traced to these ancient survivors."

Ferns were also the big survivor, as opposed to trees, because their tiny, single-celled spores dispersed quickly. Spores are much smaller than seeds, and they can easily grow in a damp area. Ferns are usually among the quickest plants to return after natural disasters.

"The spores are tiny -- you could fit four across a single strand of your hair," Regan Dunn, study co-author and paleontologist at the Field Museum in Chicago, said in a statement.

So how long would it take the ferns to thrive? They can colonize an area quickly, but it still takes time.

"It may have taken on the order of 100 years for the 'fern spike' to begin, and about 1,000 years for forest communities to rebound," Field said. "Once forests were back, the ancestors of today's modern tree-dwelling birds could -- and did -- move into the trees. By a couple of millions of years after the asteroid impact, we have direct evidence of arboreal fossil birds."

Past could mirror the future

Studying whole paleoecosystems shows how life on Earth has evolved through all the trials and tribulations of the past, Dunn said in an email.

But it's also incredibly important to study what happened during the fifth mass extinction because many scientists believe we're entering the sixth mass extinction.

"Human activity is causing deforestation on a massive scale," Field said. "We know that the diversity of bird communities is impacted by the availability of forests -- when forests are cut down in favor of, for example, palm oil monoculture, bird diversity is slashed. It's probable that, if this kind of deforestation continues unabated, it will leave an indelible signature on the evolution of birdlife."

Dunn added that "By studying this event, we learn about what happened to biodiversity in the past following destruction of Earth's ecosystems and how long it took for biodiversity to recover. On a human time-scale, recovery is very long indeed. We need to take these lessons to heart and act now to preserve today's profound biodiversity."

Indiana Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 77565

Reported Deaths: 3105
CountyConfirmedDeaths
Marion16304733
Lake7840283
Elkhart499287
Allen4103164
St. Joseph368183
Hamilton2941104
Vanderburgh208215
Hendricks1972109
Cass18099
Johnson1800119
Porter139139
Clark133350
Tippecanoe126312
Madison104866
LaPorte95730
Howard93865
Kosciusko87212
Bartholomew84447
Floyd83750
Marshall80123
Monroe77732
Delaware76852
Vigo75213
Dubois71812
Noble70829
Boone70446
Hancock69439
Jackson6065
Warrick60030
Shelby57228
LaGrange56910
Grant53230
Dearborn52228
Morgan49235
Henry46020
Clinton4564
Wayne40210
White38011
Montgomery36321
Lawrence35827
Harrison35524
Decatur34732
Putnam3288
Daviess28420
Miami2792
Scott27810
Jasper2592
Greene25634
Franklin24915
Gibson2434
DeKalb2424
Jennings23212
Ripley2208
Steuben2173
Fayette2057
Carroll2033
Perry18813
Posey1810
Starke1817
Orange17924
Wabash1795
Wells1782
Fulton1742
Jefferson1722
Knox1681
Whitley1606
Tipton15416
Sullivan1521
Washington1481
Clay1415
Spencer1393
Randolph1325
Huntington1303
Newton12110
Adams1202
Owen1101
Jay940
Rush914
Pulaski841
Fountain762
Brown752
Blackford662
Pike660
Ohio656
Benton630
Vermillion610
Parke591
Switzerland560
Martin500
Crawford480
Union410
Warren251
Unassigned0207

Ohio Coronavirus Cases

Data is updated nightly.

Confirmed Cases: 105426

Reported Deaths: 3755
CountyConfirmedDeaths
Franklin19124533
Cuyahoga13999519
Hamilton9917260
Lucas5544324
Montgomery4544101
Summit3712224
Butler307064
Marion295245
Mahoning2644258
Pickaway240442
Stark1931142
Warren187739
Lorain186777
Columbiana169960
Trumbull1578111
Fairfield144933
Delaware137819
Licking136751
Clark121815
Lake115443
Wood110158
Clermont98111
Medina97736
Miami88139
Allen81746
Tuscarawas80114
Portage78063
Greene74212
Mercer66813
Belmont62826
Richland62612
Erie61928
Ashtabula58046
Madison58010
Wayne56759
Geauga56545
Ross5204
Darke42529
Huron4135
Hancock4103
Sandusky40717
Ottawa40527
Athens3642
Holmes3316
Lawrence3230
Auglaize2866
Union2771
Scioto2601
Muskingum2561
Seneca2424
Jefferson2403
Preble2192
Shelby2194
Knox2189
Putnam21517
Washington21222
Coshocton1999
Champaign1922
Morrow1852
Hardin18012
Crawford1775
Clinton1746
Highland1692
Logan1692
Perry1643
Fulton1581
Ashland1563
Defiance1554
Wyandot1559
Brown1502
Williams1393
Fayette1260
Henry1242
Hocking1229
Guernsey1217
Carroll1145
Monroe9418
Pike800
Gallia781
Jackson780
Van Wert732
Paulding720
Adams682
Meigs630
Vinton322
Morgan310
Harrison261
Noble190
Unassigned00
Fort Wayne
Clear
64° wxIcon
Hi: 87° Lo: 66°
Feels Like: 64°
Angola
Scattered Clouds
63° wxIcon
Hi: 86° Lo: 64°
Feels Like: 63°
Huntington
Scattered Clouds
64° wxIcon
Hi: 85° Lo: 65°
Feels Like: 64°
Decatur
Broken Clouds
64° wxIcon
Hi: 86° Lo: 65°
Feels Like: 64°
Van Wert
Broken Clouds
64° wxIcon
Hi: 85° Lo: 64°
Feels Like: 64°
Weekend Storm Chances
WFFT Radar
WFFT Temperatures
WFFT National

Community Events