Soft Lung Tissue Found in Modern-Looking Bird from Dinosaur Era

For the first time, soft tissue showing details of lung structure have been found in a fossil bird said to be 120 million years old.

PNAS just printed a paper with another soft-tissue bombshell: Wang et al., “Archaeorhynchus preserving significant soft tissue including probable fossilized lungs.” It’s not the first fossil of Archaeorhynchus spathula, a pigeon-sized bird sporting a fantail and avian lungs. It’s also not the first fossil with probable lung tissue. It is, however, the first fossil showing details of avian lung tissue so well-preserved as to determine the lung structure. The soft tissue traces appear in pairs, supporting the idea that they are preserved lungs rather than other organs.

The fossil, alleged to be 120 million Darwin Years old, was found in China’s Jehol biota, but had been resting in a museum till examined by co-author Jingmai O’Connor. Live Science says,

This is the fifth described A. spathula specimen — a toothless, pigeon-size bird — but it’s by far the best preserved, O’Connor said. That’s especially because of the speckled, white material in its chest cavity that appears to be a fossilized lung.

Once again, the reports leave the nature of this “soft tissue” somewhat ambiguous: is it primordial, original biological material, or does “fossilized” indicate mineral replacement? The paper does make clear, however, that features belonging to modern birds appear in this fossil earlier than expected:

Bones of flying birds are hollow and air-filled, with girders and struts for strength. Courtesy Illustra Media.

Unusual traces of paired soft tissue structures preserved in Archaeorhynchus STM7-11 are, largely by exclusion, identified as plausible remnants of the lungs (Fig. 2), a deduction supported by topographical location and gross morphological and microscopic lines of evidence. In fact, this is not the first known record of fossilized lungs in a vertebrate; lung remains are also preserved in a Mesozoic mammal from the 125-Ma Las Hoyas Lagerstätte (25) and several Tertiary fossil amphibians (44, 45). Because EDS failed to reveal the chemical composition of the authigenic mineral forming the lung remains, we cannot attempt to explain the taphonomic processes responsible for this preservation at this time. Although not all of the main structures of the avian respiratory system could be identified on the supposed fossil lung (e.g., the very delicate air sacs that are even less likely to fossilize), the microstructure of the preserved lung closely resembles that of modern birds. This suggests that the general structural design of the avian lung has been conserved for a very long time, being already present in the most primitive members of the Ornithuromorpha, the clade that includes Neornithes, and can be presumed to have considerable functional utility.

Whether or not the authors could distinguish between mineral and biological material, they were impressed by the remarkable preservation. Laura Geggel at Live Science says,

Ancient organs rarely fossilize, so paleontologists were stunned to find the incredibly well-preserved remains of a lung that belonged to bird from the dinosaur age.

The Feathers

This fossil also has modern-like feathers preserved. Laura Geggel continues,

Initially, scientists were excited to describe the specimen of Archaeorhynchus spathula, a bird that lived about 120 million years ago, because its fossil had exquisitely preserved feathers, including a unique pintail that isn’t seen in any other Cretaceous bird, but is common in birds nowadays.

These are not imaginary feathers (15 May 2017) on a supposed “feathered dinosaur” (6 March 2014), but real feathers on a real bird. The authors distinguish the two, referring to “feathered dinosaurs and birds” in the Introduction. In all other references, this fossil is called a bird, described as “a basal member of the Ornithuromorpha [bird-shaped things], the lineage that includes neornithines” [new birds]. Latin taxonomic terms seem less imposing when translated into plain English.

Does this bird look 120 million years old? Artist conception of Archaeorhynchus. Credit: Brian Choo.

Where’s the Evolution?

Evolutionists face a dilemma placing this fossil into an evolutionary timeline. Geggel summarizes the authors’ opinion, saying, “The finding reveals that the lung structures in early birds are similar to the lungs of modern birds.” Its feathers, also, appear modern. How is this to be explained by mutation and natural selection? The authors say,

Archaeorhynchus is commonly resolved as the most basal known ornithuromorph bird, capturing a stage of avian evolution in which skeletal indicators of respiration remain primitive yet the lung microstructure appears modern. This adds to growing evidence that many physiological modifications of soft tissue systems (e.g., digestive system and respiratory system) that characterize living birds and are key to their current success may have preceded the evolution of obvious skeletal adaptations traditionally tracked through the fossil record.

In short, function preceded shape. It’s like saying that your internal organs evolved first, then your skeleton evolved to match them. Does that make sense, really? And how would scientists know that, when the organs are rarely preserved? That last sentence in the quote indicates that evolutionists could be on the wrong track looking at fossil bones alone.

As usual, the answer to how these complex organs and systems evolved, is “They evolved” (29 August 2018). Instead of explaining how things could evolve by Darwinian mechanisms (the Stuff Happens Law, 13 Oct 2018), they reason that since these complex systems provide a benefit, they must have “emerged” or “appeared” by indescribable means. The authors use another synonym for Darwinian miracles: birds “attained” their remarkable powers:

After birds attained the capacity for powered flight, they dispersed widely, and consequently underwent a notable adaptive radiation that ultimately resulted in Aves being the most speciose of the amniote clades. Among vertebrates, birds have structurally the most complex, and functionally the most efficient, respiratory system: the lung-air sac system (20, 21, 39, 40), which is capable of supporting their highly energetically demanding form of locomotion (powered flight), even in extremely oxygen-poor environments (e.g., for the bar-headed geese, which fly over the Himalayas). Although certain morphological similarities exist between the lungs of birds and those of other reptiles (41, 42), important questions on how, when, and why the modern avian lung evolved remain unclear.

Laura Geggel, peering into Darwin’s crystal ball, sees a glimmer of light, even if unclear:

O’Connor is calling the A. spathula fossil “the first informative lung remains,” because they shed light on bird evolution.

There you have it: birds “attained” powered flight. But did they attain it on their own, or was this capability, involving multiple integrated systems, imparted to them by intelligent design? (see Flight: The Genius of Birds).

Here’s the upshot: Soft tissue has been found in a remarkably preserved fossil bird possessing many modern-looking traits, including “the most complex, and functionally the most efficient respiratory system” in the animal kingdom. These soft tissue impressions survived in exquisite detail for 120 million Darwin Years. The bird resembled a pigeon, with modern-looking fantail feathers. Scientists classified it as a “new bird” in the category “bird-shaped things.” Aren’t you glad you have experts to “shed light” on evolution for us?