Fossils of the "H Animal" and "Y Animal" discovered at Mazon Creek, near Braidwood, Illinois. A 310 million year old mystery.

The “H Animal," Etacystis Communis.
It was a soft-bodied invertebrate that lived in shallow tropical coastal waters of muddy estuaries (where the tide meets the stream) during the Pennsylvanian geological period, about 310 million years ago. Many exquisitely preserved specimens are found in the ironstone nodules that make up the deposits.

The majority of collecting areas are the spoil heaps of abandoned coal mines, the most famous of which is Peabody Coal Pit 11. Francis Creek shale pit 11 now serves as a cooling pond for the Braidwood nuclear power plant, but with over 100 other localities, specimens still come to light.

It is thought to be a filter-feeding organism that grew throughout its lifetime, achieving a maximum length of 4.3 inches.

A little hard to see, but look at the darker "H" in the center of the fossil.

The classification is uncertain. The animal had a unique H-shaped body ranging from 3/4 inch to 4.3 inches long, and researchers have suggested a hemichordate (wormlike marine invertebrates) or hydrozoan (relatives of jellyfish) affinity. Examples of the H Animal have been found only in the Mazon Creek (River) fossil beds in Illinois.

The “Y Animal," Escumasia Roryi.
It is a puzzling creature. It has only found in the Peabody Coal Pit 11 of the Mazon Creek formation. The only species of the subfamily, it is Y-shaped, bilaterally symmetrical, soft-bodied and is about 6 inches in length.

It appears to have a mouth slit on the top between the two arms and a second opening on one side of the main body, presumably an anus, though there is no proof that it is an anus. It is attached to the sea floor by a stalk attached to a round base. Oddly, a specimen appears to have a short tube-like structure in between the two arms near the mouth.

Because of the lack of complex structures or apparent internal organs, it is believed that it must have been related to coelenerates (cnidarians) and may have used stinging nematocysts on its arms to capture prey. However, because of its bilateral symmetry and second opening, it can’t fit the technical definition of a coelenerate. 

Therefore, it is considered a separate group that may have broken off of the cnidarians and gone extinct as a failed evolutionary experiment. If it were to be classified as a coelenerate, the definition of coelenerate would have to be changed and a new class would have to be added.

Compiled by Neil Gale, Ph.D.

Illinois' Greatest Fossil Mystery... Solved!

Since 1955, when amateur fossil hunter Francis Tully discovered an unlikely prehistoric creature in a coal mining area near Morris, Illinois, 55 miles south-west of Chicago, the 'thing' that was named Tullimonstrum (Tully monster) has presented one of the great puzzles in paleontology.

A Tully Monster in Motion.

Much as the people of Metropolis wondered whether Superman flying overhead was a bird or a plane. Scientists have struggled to classify these fossils that showed traits associated with several disparate animal types and such abnormalities as eyes mounted on an external bar and a long, toothy proboscis.

If you put a worm, a mollusk (snails, slugs, mussels, and octopuses), an arthropod (insects, spiders), and a fish in a box and shook it up, then you'd have a Tully monster, in the end. Paraphrased from Carmen Soriano, a paleontologist at Argonne National Laboratory.

Tullimonstrum gregarium, dorsal view, from an article titled, "The Tully monster is a vertebrate," in the Field Museum of Natural History's "Nature magazine."

The Tully's renown even stretched to the Illinois state legislature, which named it the official state fossil in 1989, some 308 million years after it inhabited the shallow salty waters that turned into Illinois' Mazon Creek geological deposits in Grundy County, one of the richest fossil troves on Earth.

sidebar

About 540 million years ago, between the Gondwana and the Laurasia supercontinent [1] periods, when the Earth was about 4 billion years old, Illinois was south of the equator for the second time. Illinois was part of a low-lying basin covered by a shallow, warm tropical sea. As land masses shifted over time, this saltwater became trapped in aquifers that still exist underground today.

However, Tullimonstrum gregarium has a home on the Tree of Life rather than in the biological category known as the "problematica." Utilizing the synchrotron X-ray machine at Argonne and the Field Museum's collection of 2,000 Tully specimens, a team from those two institutions, Yale University and the American Museum of Natural History announced in a paper published in the journal "Nature" on March 16, 2016, that "The Tully monster is a vertebrate."

Morphology and Phylogeny of Tullimonstrum.
CLICK FOR A FULL-SIZE VIEW.

a: Chordate phylogeny including Tullimonstrum gregarium; lampreys in yellow; hagfishes in orange.
b: Reconstruction of Tullimonstrum. 
c: Tullimonstrum, oblique lateral view: 
    Eyb; eyebar; 
    My; myomeres; 
    GP; gill pouches; 
    CF; caudal fin; 
    No; notochord; 
    OtL; otic lobe, and OpL; optic lobe of the brain and dorsal fin.
d: Line drawing: black, teeth; brown, lingual organ; light grey, eyebar; dark green, gut and oesophagus;  ed, notochord; light green, brain; orange, tectal cartilages; pink, naris; purple, gill pouches; yellow, arcualia; dark blue, myosepta; blue with black stripes, fins with fin rays.

Below that headline, the paper describes Tully as belonging "on the stem lineage to Lampreys (an ancient extant lineage of jawless fish)," a find that "resolves the nature of a soft-bodied fossil which has been debated for more than 50 years."

"This is one of the mysteries that I heard about since I was a kid," said Soriano. "To be able to study, to basically 'unmonsterize' the monster, is really exciting."

"Resolving this is a big deal," said Scott Lidgard, the Field Museum's associate curator of fossil invertebrates and another of the paper's authors. "It's one of the examples used in textbooks around the world as what is called 'problematica,' " creatures that defied ready classification and were sometimes thought to be examples of extinct phyla or animal categories.

"This is kind of a poster child for that sort of evolutionary puzzle," Lidgard said. The finding "changes it from a mystery to a fishlike organism that is probably on the lineage leading to what we would recognize as lampreys."

An artist's reconstruction shows the Tully Monster, a type of jawless fish called a lamprey, as it would have looked 310 million years ago in this image.

It's also a big moment for those who study lesser prehistoric animals and realize, said Lidgard, that "we're never going to be as popular as dinosaurs and fossil birds."

The Tully monster is named for its assemblage of features, not for any sort of fearsome size. The biggest of the many specimens that have been found suggested a maximum length of about 18 inches and a typical length of 12 inches.

But because Mazon Creek fossils are so well preserved, there is a lot of Tully to study. Skeletons have not survived, but detailed impressions in stone have.

"If you see the specimens, they are typically well preserved," Soriano said. "It's not that they are a blob in the rock."

Tully, a pipefitter for Texaco and lifelong fossil hound, described his find to the Tribune in a story in 1987, also the year of his death:

"I found two rocks that had cracked open from natural weathering. They held something completely different. I knew right away. I'd never seen anything like it. None of the books had it. I'd never seen it in museums or at rock clubs. So I brought it to Chicago to the Field Museum to see if they could figure out what the devil it was."

Another artist's artwork shows the Tully Monster.

The first scientific paper describing the Tully monster and its vivid Latin name came in the mid-1960s from one of Lidgard's predecessors at the museum, who "thought it was a worm," Lidgard said.

Later papers proposed that it was a "free-swimming shell-less snail," he said, and then a conodont, an extinct eel-like creature very rare in the fossil record.

"I've been looking at this thing for 30 years," said Lidgard. "Years ago, I had a stab at it, thinking it might be related to squids. We gave up. We didn't publish anything."

What got the ball rolling again was Lidgard hearing about Victoria McCoy, a Yale grad student exploring the Mazon Creek deposits who would become the paper's lead author.

They met at a 2014 conference, and the following year, an assembled team spent three weeks at the Field Museum studying its Tully specimens.

The Department of Energy's Argonne National Laboratory, southwest of Chicago, came into the picture because of its advanced imaging techniques using the Advanced Photon Source, an electron accelerator and storage ring that "provides ultra-bright, high-energy storage ring-generated x-ray beams for research in almost all scientific disciplines," according to Argonne.

"The thing with these machines is they are incredibly powerful microscopes," Soriano said. "We can get information not only on the morphology of the sample but also on the structure and composition."

It allows people "to see what no one saw before basically," she said.

What the scientists saw as they studied the Argonne imagery, digital photographs of the fossils, and the fossils themselves were characteristics that tied the Tully monster to lampreys.

For instance, a chemical analysis of the eyestalks showed the presence of zinc, "very similar to the material in the eyes of vertebrate fossil fishes," said Lidgard.

"Tully is usually preserved so that you're looking down on its back," he added. "Every so often, you can see its side. In those twisted fossils, we found very few where we think we can distinguish openings we interpret as openings to a particular kind of gill structure present in very primitive fishes like lampreys."

And they were able to find the animal's gut trace, as well as the shadow of its digestive system, in the lower part of the body, which suggested that what had previously been thought to be a gut trace up on the back was, in fact, a notochord, a flexible rod in the back.

That made it a primitive vertebrate, he said. He does not recall a moment where somebody said, "Hey, lamprey!" but recalls that "it became more and more clear," he said. "As those results started coming in, it was pretty convincing immediately."

So if the Tully monster is now a known vertebrate lamprey ancestor with a place in the historical animal record, that raises two big questions:

First, do all those specimens at the Field Museum move out of the invertebrate department?

Paul Mayer, collections manager of invertebrate fossils, laughed. "I've been talking with the vertebrate fossil collection manager," he said. "We'll wait a few years and make sure there's no rebuttal. It's a lot of work to move these things up the stairs to where his collection is."

Question two: Does the Tully monster need to be renamed?

"No, because it's still a monster," said Soriano. "It's something really different from anything we have seen. It's one of a kind. If you return to this idea of a monster as anything strange, it's still strange."

ADDITIONAL READING: Prehistoric Saltwater Shark Nursery Fossils Found in Illinois.

Compiled by Dr. Neil Gale, Ph.D. 

---

[1] EARTH'S SUPERCONTINENTS HISTORY:

Vaalbara...............3,636–2,803 (million years ago)

Ur.....................2,803–2,408 (million years ago)

Kenorland..............2,720–2,114 (million years ago)

Arctica................2,114–1,995 (million years ago)

Atlantica..............1,991-1,124 (million years ago)

Columbia(Nuna).........1,820–1,350 (million years ago)

Rodinia................1,130–750 (million years ago)

Pannotia...............633-573 (million years ago)

Gondwana...............596-578 (million years ago)

Laurasia & Gondwana....472-451 (million years ago)

Pangaea................335-175 (million years ago)

---

The Tully monster was a soft-bodied invertebrate found only in Illinois and is the official Illinois state fossil. Look how cute he is!

You can own your own cute 12" soft-bodied Tully monster plushy from Paleozoic Pals.

The Kinderhook plates were discovered in 1843 in an Indian mound near Kinderhook, Illinois.

The Kinderhook plates are a set of six small, bell-shaped brass pieces with strange engravings claimed to have been discovered in 1843 in an Indian mound near Kinderhook, Illinois.

CLICK FOR A FULL-SIZE IMAGE.

Purported Discovery
On April 16, 1843, Robert Wiley, a merchant living in Kinderhook, began to dig a deep shaft in the center of an Indian mound near the village. It was reported in the Quincy Whig that the reason for Wiley's sudden interest in archaeology was that he had dreamed for three nights in a row that there was treasure buried beneath the mound. At first, he undertook the excavation alone, and reached a depth of about ten feet before he abandoned the work, finding it too laborious an undertaking. 

On April 23, he returned with a group of ten or twelve companions to assist him. They soon reached a bed of limestone, apparently charred by fire. Another two feet down, they discovered human bones, also charred, and "six plates of brass of a bell shape, each having a hole near the small end, and a ring through them all, and clasped with two clasps". A member of the excavation team, W. P. Harris, took the plates home, washed them, and treated them with sulphuric acid. Once they were clean, they were found to be covered in strange characters resembling hieroglyphics.

The plates were briefly exhibited in the city, and then sent on to Joseph Smith, the founder of the Latter Day Saint (Mormon) movement. Twenty years earlier, on September 22, 1823, Smith claimed to have uncovered a set of golden plates, and, according to Latter Day Saint belief, translated them into the Book of Mormon. The finders of the Kinderhook plates, and the general public, were keen to know if Smith would be able to decipher the symbols on the Kinderhook plates as well. The Times and Seasons, a Latter Day Saint publication, claimed that the existence of the Kinderhook plates lent further credibility to the authenticity of the Book of Mormon. Parley Pratt wrote that the plates contained Egyptian engravings and "the genealogy of one of the ancient Jaredites back to Ham the son of Noah."

Smith's Response
Smith's private secretary, William Clayton, recorded that upon receiving the plates, Smith sent for his "Hebrew Bible & Lexicon," suggesting that he was going to attempt to translate the plates by conventional means, rather than by use of a seer stone or direct revelation. On May 1st, Clayton wrote in his journal:

I have seen 6 brass plates... covered with ancient characters of language containing from 30 to 40 on each side of the plates. Prest J. [Joseph Smith] has translated a portion and says they contain the history of the person with whom they were found and he was a descendant of Ham through the loins of Pharaoh king of Egypt, and that he received his kingdom from the ruler of heaven and earth.

The History of the Church also states Smith said the following:

I have translated a portion of [the plates] and find they contain the history of the person with whom they were found. He was a descendant of Ham, through the loins of Pharaoh, king of Egypt, and that he received his kingdom from the ruler of heaven and earth.

Stanley B. Kimball says the statement found in History of the Church could have been an altered version of William Clayton's statement, placing Smith in the first person. Diane Wirth, writing in Review of Books on the Book of Mormon (2:210), states: 

"A first-person narrative was apparently a common practice of this time period when a biographical work was being compiled. Since such words were never penned by the Prophet, they cannot be uncritically accepted as his words or his opinion."

Rediscovery, Analysis, and Classification as a Hoax
The Kinderhook plates were presumed lost, but for decades The Church of Jesus Christ of Latter-day Saints (LDS Church) published facsimiles of them in its official History of the Church. In 1920, one of the plates came into the possession of the Chicago Historical Society (now the Chicago History Museum). In 1966, this remaining plate was tested at Brigham Young University. The inscriptions matched facsimiles of the plate published contemporaneously, but the question remained whether this was an original Kinderhook plate, or a later copy.

Though there was little evidence of whether the Kinderhook Plates were ancient or a contemporary fabrication, some within the LDS Church believed them to be genuine. The September 1962 Improvement Era, an official magazine of the church, ran an article by Welby W. Ricks stating that the Kinderhook plates were genuine. In 1979, apostle Mark E. Petersen wrote a book called "Those Gold Plates!" In the first chapter, Peterson describes various ancient cultures that have written records on metal plates.

Then Peterson claims: "There are the Kinderhook plates, too, found in America and now in the possession of the Chicago Historical Society. Controversy has surrounded these plates and their engravings, but most experts agree they are of ancient vintage."

In 1980, Professor D. Lynn Johnson of the Department of Materials Science and Engineering at Northwestern University examined the remaining plate. He used microscopy and various scanning devices and determined that the tolerances and composition of its metal proved entirely consistent with the facilities available in a 19th-century blacksmith shop and, more importantly, found traces of nitrogen in what were clearly nitric acid-etched grooves. 

This matches what was stated in an 1879 letter to James T. Cobb, in which Wilbur Fugate confesses to the hoax: "Wiley and I made the hieroglyphics by making impressions on beeswax and filling them with acid and putting it on the plates. When they were finished we put them together with rust made of nitric acid, old iron and lead, and bound them with a piece of hoop iron, covering them completely with rust". According to Fugate, Wiley had planted the plates at the bottom of the hole he had dug in the mound, before fetching a group of others to witness the discovery.

In addition, Johnson discovered evidence that this particular plate was among those examined by early Mormons, including Smith, and not a later copy. One of the features of the plate was the presence of small dents in the surface caused by a hexagonally-shaped tool. Johnson noticed that one of these dents had inadvertently been interpreted in the facsimile as a stroke in one of the characters. If the plate owned by the Chicago Historical Society had been a copy made from the facsimiles in History of the Church, that stroke in that character would have been etched, like the rest of the characters. He concluded that this plate was one that Smith examined, that it was not of ancient origin, and that it was in fact etched with acid, not engraved.

In 1981, the official magazine of the LDS Church ran an article stating that the plates were a hoax, and asserted that there was no proof that Smith made any attempt to translate the plates: "There is no evidence that the Prophet Joseph Smith ever took up the matter with the Lord, as he did when working with the Book of Mormon and the Book of Abraham."

The Confession
According to Wilbur Fugate in 1879, the plates were carefully forged by himself and two other men from Kinderhook, Bridge Whitten and Robert Wiley, who were testing the validity of the claims made by Joseph Smith, founder of the Latter Day Saint movement, at that time headquartered in Nauvoo. According to Latter Day Saint belief, the Book of Mormon was originally translated by Smith from a record engraved on golden plates by ancient indigenous people.

Compiled by Neil Gale, Ph.D.