The late Cretaceous was the fullest world
That life had ever made.
From pole to pole
The forests grew: no ice, the planet hurled
Into a greenhouse warmth that filled the whole
Of the equator and the polar zone
With the green of Angios' flowering empire
And Conifera's ancient evergreen throne—
The world was warm, the world was entire
In its coverage of life from the abyss
Of the ocean's deepest trench to the highest
Mountain that the Cretaceous tectonic bliss
Of activity could raise—the slightest
Corner of the planet held its life.
In the sea: Mosas ruled the shallows,
His serpentine bulk the greatest knife
That the Cretaceous marine world allows
For cutting through the ocean's living wealth—
And Plesios still dove with her four flippers
Through the deeper water, the stealth
Of the plesiosaur unchanged, the sippers
Of the ocean's fish for a hundred million years.
The ammonites spiraled through the water column
In their chambered shells, the ancient peers
Of Coleios' cuttlefish—the solemn
And beautiful geometry of the chambered nautilus
Still sailing, as it had since the Ordovician sea—
And the teleosts, Teleosteos' fabulous
And overwhelming diversity,
Filled every marine niche from reef to open water,
From freshwater lake to the ocean's midnight zone—
Half of all vertebrates, each the daughter
And son of Actinus' ancient bone.
On land: Tyrannos stalked his kingdom
And Ceratops bore his horns against the king—
Hadros called across the freedom
Of the Cretaceous plain, and the spring
Of every year brought the ornithischian herds
In their annual migrations, millions strong,
Across the continents—and the early birds
Of Archaeos' lineage sang their song
In the canopy, already diversified
Into waterbirds and shorebirds and the small
And toothed Cretaceous forms that occupied
The niches that the pterosaurs could not fill—all
The understory and the forest interior
Where the pterosaur's wingspan could not reach.
Pteros' children ruled the aerial superior
Of the open sky, and on every beach
And flatland stalked the azhdarchids, tall
As giraffes and winged as nightmares.
In the undergrowth, Mammos kept his small
And quiet vigil—the nighttime prayers
Of the mammalian line continuing their watch
Through the Cretaceous as through the Jurassic
And the Triassic before: the notch
Of smallness, the nocturnal and gymnastic
Survival of the warm-blooded and the furred
In the shadow of the cold-blooded giants—
But by now the mammals had diversified: the word
Of the Cretaceous mammal was defiance
In miniature—multituberculates with their
Rodent-like teeth, the metatherians
Who carried pouches, and the rare
And small eutherians—the contrarians
Who would one day rule the world but for now
Were the size of a mouse and twice as humble.
The insects numbered more than all the vowed
And vertebrate species combined—the tumble
And buzz of Neopter's children in the flowers
Of Angios was the soundtrack of the age:
Bees and wasps and butterflies, the hours
Of pollination filling every page
Of the Cretaceous day with the hum
Of the partnership between the plant and wing.
This was the peak. This was the sum
Of the Mesozoic's offering:
A world more full of life than it had been
Before the Permian's Great Dying—more diverse,
More complex, more intricately between
The predator and prey, the universe
Of ecological interaction reaching depths
Of sophistication that the Paleozoic
Had never known—and in these depths
The Mesozoic wrote its most heroic
And beautiful chapters: the world at its most alive,
The planet at its greenest and most full,
Every niche occupied by whatever could thrive
In the Cretaceous greenhouse's generous pull.
Honor the peak—the moment when the world
Was most itself, most full, most densely woven
With the living—every flag unfurled,
Every niche occupied, every kingdom cloven
To its finest divisions—the pinnacle
Of the Mesozoic's hundred-and-eighty-million years
Of building—the invincible
And the beautiful, the joys and the fears
Of the most complex world that had ever been.
What came next was the asteroid.
But tonight the world is at its most serene,
And the peak is not yet destroyed.