Coprolites, Gut Contents, and Feeding Traces

"[T]he data represent a single brief event, probably of the order of hours, and at the end of one individual animal's life." — Caleb Brown and colleagues, on the last meal of the armoured dinosaur Borealopelta, 2020¹

"A consistent creationist interpretation means all this activity occurred before Day 150 during the Flood year (when the waters reached their peak). But how can this be?" — Michael Oard, on scavenged dinosaur bonebeds, 2023²

Summary

A feeding trace is a record of an animal eating.  It can be a meal still in the gut, a dropping, a bite, or a hole bored into bone, wood or rock.  Each takes time to make, and the time can be measured on living animals.  This article asks how much time each kind needs, and whether young-earth Flood models can fit it inside the Flood year.  The answer depends on where the clock ran.

1. Two kinds of clock.  Some traces record time spent inside a living animal:  a meal being digested, a wound healing, a stomach filling with hard parts.  A Flood model can spend that time before the Flood began, so these traces cost the Flood year nothing.  Other traces record time spent on a surface after the dung was dropped or the animal died:  dung drying and being worked by beetles, carcasses rotting and being bored, bones on the seafloor being colonised by worms.  If the rock is a Flood deposit, that time has to fit inside the Flood year.

2. Gut contents fit a Flood, and point to fast burial.  The young-earth writers are right about this.  The last meal of the nodosaur Borealopelta records "a single brief event, probably of the order of hours," and the animal ended up in marine rock 200 to 400 km from the shore of its day.¹¹  Harold Coffin, Andrew Snelling and Tim Clarey all use stomach contents as evidence of fast burial, and they are right to.

3. Healed bites fit a Flood too.  A Tyrannosaurus tooth sits in a hadrosaur's tail inside healed bone.  Its describers say the hadrosaur "could have lived from several months to perhaps a number of years after the attack."³  That is time in the animal's life, not on a Flood surface.

4. So do shipworm borings in drifted wood.  A living shipworm in a floating panel bored 48 mm in its first month and 797 mm in nine.⁴⁴  A bored log needs weeks to months in seawater, and a Flood with floating log mats supplies that.

5. Dung worked on the ground needs about a day per surface, and more.  Coprolites in the Kaiparowits Formation of Utah, at three or more levels, carry burrows like those of dung beetles, and snails "had sheltered and fed within dung pats that were already deposited."⁵⁵  Living dung beetles do most of their work 24 to 48 hours after a pat falls.⁶  The Triassic latrines of the Chañares Formation, Argentina, hold up to 94 coprolites per square metre, and those outside concretions "show some degree of weathering exposure with cracks and pits."⁷⁷  ICR's Clarey read the latrines as animals "trapped by rising water for several days."⁸  The arithmetic in Part 3 shows a herd of several hundred could do it.  But his article reverses which coprolites the authors found weathered.

6. Bored carcasses and bones need one to two months.  Oard's model already puts scavenging on its briefly exposed surfaces, and his book defines the dinosaurs' stay there as their "final hours or days."⁹¹⁰  Beetle borings and pupal chambers in dinosaur bone need a carcass that has dried and then about five weeks or more for the beetles to grow.¹¹  Bone-eating Osedax worms settle on bone "as rapidly as two months" after it lands, and their borings are known in Cretaceous plesiosaur bone.¹²¹³  There is a fair young-earth escape:  bones bored before the Flood and carried in by it cost nothing.  No one has tested which bored bones were bored in place.

7. Every minimum is soft, taken one surface at a time.  None needs more than a few months, and Oard gives land animals up to 150 days.  The cost comes from stacking:  the same surfaces also carry tracks and nests, and sections stack many such surfaces.  That sum belongs to Briefly Exposed Diluvial Sediments.  The table in Part 7 gives it the inputs.

Verdict.  For traces made inside a living animal or in seawater, the Flood answer holds, and the young-earth argument from gut contents to fast burial is sound.  For traces made on a surface after defecation or death, the Flood answer is unfinished.  They need from a day to two months each, more than the "final hours or days" BEDS describes for the longer ones, and no young-earth writer has priced dung-beetle work, carrion-insect borings or Osedax borings.

Part 1: The young-earth position, in its own words

The problem as Oard states it

Michael Oard is the young-earth writer who has done most to explain traces of living animals inside rock his model puts in the Flood.  In 2023 he set out the challenge plainly.  Dinosaur bonebeds sit "in the midst of sequences of Flood-deposited layers," and many "show signs that the carcasses were scavenged after death.  There are tooth marks on the bones … and even broken-off teeth of carnivorous dinosaurs."  He goes on:  "A consistent creationist interpretation means all this activity occurred before Day 150 during the Flood year (when the waters reached their peak).  But how can this be?"²

His answer is the model he calls BEDS, briefly exposed diluvial sediments.  "In areas with rapid deposition of sediments, a brief drop in the level of the Floodwaters would expose a flat bedding plane (BEDS).  Dinosaurs swimming or on higher land nearby could move onto the BEDS and thus make tracks, lay eggs, and scavenge dead dinosaurs."⁹  The animals "could land on such an area and remain for a time until it was flooded again."²  Because the water rose and fell many times, "tracks, as well as eggs, and scavenged bonebeds, can occur at multiple levels in an area."²

Two numbers bound the model.  All of it happens before Day 150, when "all air breathing animals on land died."¹⁴  And for eggs and tracks Oard narrows the window to "between Day 40 and about Day 120 of the Flood."¹⁵  How long a single exposure lasts is less clear.  His 2011 book, as Brian Thomas quotes it in a review for Creation Ministries International, says the dinosaur data can be explained "by their final hours or days being spent on the freshly-laid-and-then-exposed flat Flood sediments."¹⁰  At Lark Quarry in Australia he has the water rising and falling in "a matter of seconds to possibly a few minutes."⁹

So BEDS already contains scavenging by name.  It does not mention dung, gut contents, healed wounds or borings.  Oard's book was not available to this article;  the review quotes no passage from it on any of these.

Gut contents and dung as evidence of fast burial

Young-earth geologists have used fossil meals as evidence of fast burial for forty years.  Harold Coffin, a paleontologist at the Seventh-day Adventist Geoscience Research Institute, described an ichthyosaur from the English coast whose stomach held hundreds of thousands of squid-like hooklets.  He concluded:  "In both cases the burial was quick and the preservation good.  Modern animals that die in water or on land decay, the bones become disconnected, and scavengers and predators finish the work of destroying the evidence.  Death and permanent deep burial by catastrophic conditions appears necessary."¹⁶  Andrew Snelling, writing for the Institute for Creation Research, quotes a description of the German lignite at Geiseltal in which "the stomach contents of beetles, amphibia, fishes, birds and mammals provide direct evidence about eating habits," and draws the same conclusion:  "unusual transport and rapid burial mechanisms would have been required."¹⁷  Of a Cretaceous limestone in Mexico he notes that "Coprolites, presumably from the fish, are also quite common."¹⁷  In 2025 Tim Clarey of ICR described a pregnant ichthyosaur from Chile:  "Inside her body were fossilized fish vertebrae, which indicate that her last meal had not yet been digested."¹⁸

Leonard Brand and Arthur Chadwick, two Adventist geologists who accept a short chronology, add a mechanism.  "Some Cenozoic vertebrate fossil deposits appear to be entirely composed of bone fragments from predator dung or owl pellets.  This could also happen during a catastrophic episode if large numbers of scavengers and predators were active.  Perhaps the result would be fairly rapid processing of prey animals into bones ready for burial."¹⁹

Latrines, scavenged bonebeds, and the time they take

Only one young-earth article prices a pile of dung, and it does so in words.  In 2013 Clarey wrote about eight Triassic dung heaps in Argentina, the Chañares latrines.  He placed the rock in "middle-to-late Flood sediments" and wrote that "The concentration of coprolites found in the rocks in Argentina suggests the reptiles were surrounded and trapped by rising water for several days."⁸⁸  He concluded that "The great Flood still provides the mechanism for virtually all the fossils we find—even coprolites."⁸

Paul Garner, writing for Answers in Genesis about a Wyoming bonebed of the duck-billed dinosaur Edmontosaurus, gives a scavenging window in words too.  "Some of the bones bear tooth marks," and the excavators propose that "tens of thousands of Edmontosaurus perished in some kind of catastrophe, after which their carcasses lay around just long enough to rot and be scavenged."²⁰

Brand and Chadwick are the most candid.  "If at least the Paleozoic and Mesozoic were deposited within a year … then most animals must have been buried very soon after death—within hours or days."  Yet "Most of these disarticulated remains probably required several weeks or months of decay and disarticulation before burial.  Is it possible to fit many episodes of several months of disarticulation into a one-year Cambrian to Cretaceous process?"¹⁹  They leave the question open.

Bites, borings and the Fall

Todd Wood, a young-earth biologist, lists the evidence that animals ate meat before the Flood:  "bones with tooth marks on them?  Even better:  bones with tooth damage that has healed, indicating that there was some kind of attack while the animal was still alive.  You could also look at stomach contents or even coprolite (fossil feces) contents."²¹  Creation Ministries International, reporting the giant tyrannosaur coprolite, put predation and scavenging "both only possible after the Fall."²²  Whether animals ate meat before the Fall is argued in Death Before the Fall.  This article asks only how long the traces take.

On borings the young-earth literature has one technical paper, on hardgrounds.  John Woodmorappe accepts that some bored and encrusted seafloors are real and puts them in the Flood:  "actual in situ hardgrounds formed in a matter of months during lulls in Flood action."²³  Hardgrounds are argued in Flat Gaps and Chalk, Limestone, and the Flood.

What the young-earth literature has not addressed

Searches of the Answers in Genesis, ICR and CMI websites, which carry the Journal of Creation and Answers Research Journal, and of the Creation Research Society Quarterly, found no young-earth treatment of these:  dung-beetle burrows in coprolites;  insect borings in dinosaur bone;  Osedax borings in Mesozoic marine-reptile bone;  shipworm borings in fossil wood or peat;  the stomach contents of Borealopelta;  or a healing time for any healed bite.  No young-earth source gives a digestion time or a gut-passage time.  Wood's list names healed bites but prices none.

There is also a second young-earth camp.  Paul Garner argued in 1996 that the dinosaur nesting grounds are too much for the Flood year:  "The occurrence of in situ eggs and nests in Triassic, Jurassic, and Cretaceous sediments indicates that at least these systems must be post-Flood."²⁴  John Whitmore and Garner later proposed criteria for sorting Flood from post-Flood rock and wrote that "bioturbation could have occurred during the Flood on select horizons."²⁵  On that view many of the traces below are post-Flood and cost the Flood nothing.  The organisations publish both views.  Fossil Nests and Eggs sets out the disagreement.  This article tests the majority view, that the Mesozoic is Flood rock.

Part 2: Gut contents, a clock inside the animal

A gut content is food still inside the body when the animal died.  Adrian Hunt, who set the terms paleontologists use, groups all fossil food remains as bromalites:  "Within bromalites, there are three main subdivisions:  coprolites, cololites, and regurgitalites."  Coprolites are dung, regurgitalites are vomit, and "Cololite is restricted to in-situ intestinal fillings."²⁶  It records two short intervals:  the time from the meal to death, and the time from death to burial before the stomach rotted open or a scavenger tore it out.  Both are short.  That is why the young-earth writers in Part 1 are right to use gut contents as evidence of fast burial.

Borealopelta: a meal of hours, buried at sea

The best-described dinosaur stomach belongs to Borealopelta markmitchelli, an armoured nodosaur found in an open-pit oil-sands mine in northern Alberta.  Caleb Brown of the Royal Tyrrell Museum and six colleagues tested the mass in its belly against fourteen criteria, including its position in the body, the gastroliths in it, and whether it was carried with the carcass, and concluded it is the animal's last meal.¹  It is 88% leaf tissue, mostly ferns, with stems, twigs, and 6% charcoal.¹

The authors are explicit about what the meal measures:  "the data represent a single brief event, probably of the order of hours, and at the end of one individual animal's life."¹  A twig in it has an incomplete outer growth ring, "consistent with the twig being consumed mid-growing season, probably in late spring to mid-summer."¹  The charcoal shows "that the environment occupied by the animal prior to death was recently subject to wildfire," and the authors suggest the nodosaur, like many modern grazers, fed on ferns regrowing after a fire.¹

The animal was not buried where it ate.  It lies near the base of a 3 m glauconitic sandstone in the fully marine Clearwater Formation, deposited "in the lower shoreface to offshore transition zone," in the same unit that has yielded articulated ichthyosaurs and plesiosaurs.  "The Albian coastline lay 200–400 km to the west."¹¹

Every part of this fits a Flood account.  A land animal ate, died within hours, was carried far out to sea with its stomach intact, and was buried before the stomach decayed.  The months of fern regrowth after the fire happened before the meal, on land that is not in this rock.  A Flood model can put them before the Flood or in its first weeks.  Nothing here has to happen on a Flood-deposited surface.  The young-earth side has not written about Borealopelta, but it could, and it would be right.

An ichthyosaur stomach that took months or years to fill

A gut content can also record a long time, and a Flood account still fits it.  In 1968 John Pollard described a small ichthyosaur from the Lower Lias of Lyme Regis, Dorset, whose stomach held an oval mass of belemnite arm hooklets.  He counted about 500 hooklets per square centimetre on the exposed surface, estimated the mass at ten layers deep, and arrived at "45,000±7,000×10±4 = 478,000±250,000 or 478,000±53 per cent."²⁷  At about 300 hooklets per belemnite, "The gastric contents described here, therefore, could represent between 760 and 2,430 digested individual belemnites."²⁷  The hooklets were not passed:  ichthyosaur coprolites hold fish bones but no hooklets, just as sperm whales keep squid beaks in the stomach and periodically vomit them.²⁷  Pollard concluded that "The length of time of accumulation of these belemnoid hooklets in the ichthyosaur stomach is impossible to ascertain.  It could represent several meals or a lifetime's accumulation," and judged the animal young.²⁷

Coffin used this specimen in 1983 and conceded the point:  "how could an ichthyosaur eat so many except over a period of time?"¹⁶  His numbers are a little off.  He wrote that "one cut through the petrified gastric mass revealed approximately 45,000 hooklets" and that the total was "somewhere between 228,000 to 478,000."¹⁶  Pollard's 45,000 is a count of the surface, not a cut, and his range runs from 228,000 to 728,000.  Both slips understate the count and neither changes the argument.

The clock in this stomach ran for as long as the animal lived.  It ran inside the animal, and the animal could have been eating belemnites for years before the Flood.  Its death and burial were quick.  So the Flood answer holds here too.

Other stomachs, and how long a meal lasts

A partial skeleton of the tyrannosaurid Daspletosaurus from the Two Medicine Formation of Montana holds acid-etched bones of juvenile hadrosaurs.  "The surface corrosion exhibited by the hadrosaur elements matches that produced by stomach acids and digestive enzymes in a wide variety of living vertebrates."²⁸  Snelling cites a Brazilian Cretaceous fish with "no fewer than 13 small fish in its alimentary tract."¹⁷  A large ichthyosaur, Temnodontosaurus, from the Lower Jurassic Posidonia Shale of Germany left both a regurgitalite, "a coiled-up juvenile Stenopterygius skeleton," and a stomach holding several newborn ichthyosaurs at different stages of digestion.  Giovanni Serafini and colleagues read the stages as prey "ingested at different times (possibly days apart)," and add that the last kill "must have shortly preceded the death of the Temnodontosaurus, either by hours or a few days at most."²⁹²⁹  The ichthyosaur Clarey described in 2025 had fish vertebrae in its body.¹⁸

Living reptiles show how long such a meal stays recognisable.  In ten captive spectacled caimans, a radiographic marker took on average 117 hours to pass through the gut in females and 86 hours in males.³⁰  A crocodilian therefore holds food for three to five days.  A fossil reptile with a recognisable meal in its stomach died within days of eating at most, and was buried before the soft parts around the meal decayed.

Verdict on gut contents:  the Flood answer holds.  The clock runs inside a living animal and stops at death.  Gut contents are evidence of fast death and fast burial, as Coffin, Snelling and Clarey say, and nothing about them needs time on a Flood surface.

Part 3: Dung, and how long it lay on the ground

A coprolite is fossil dung.  It carries two clocks.  The first runs inside the animal, from meal to dropping, and costs a Flood nothing for the reason given in Part 2.  The second starts when the dung hits the ground and stops when it is buried.  A dropping buried at once records almost no time.  A dropping that dried, cracked, and was dug into by beetles records days.  Which kind a coprolite is depends on what is on it.

Coprolites that record almost no time

Many coprolites show no sign of having lain exposed, and the authors say so.  Crocodilian coprolites from the Late Eocene of Na Duong, northern Vietnam, keep delicate mucous layers on their surfaces.  "The taphonomic history of coprolites involves three main stages:  before final burial, after final burial, and after exposure.  In the case of the Na Duong coprolites, the third stage did not occur, as indicated by the well-preserved delicate mucosal layers on the outer surface."³¹  Karen Chin and colleagues found muscle fibres preserved in a tyrannosaurid coprolite from Alberta and read them as evidence of "a relatively short gut-residence time, rapid lithification, and minimal diagenetic recrystallization," adding that "Rapid burial of the feces probably was facilitated by a flood event on the ancient coastal lowland plain."³²  The flood they mean is a river flood on one plain.  But the point stands:  that dropping was buried soon after it fell.

The giant tyrannosaur coprolite from Saskatchewan that Creation Ministries International reported is 30 to 50% bone, and "The main portion of the mass was found in situ in a bentonitic mudstone."³³³³  Its describers drew no time from it.  Neither need anyone else.

A dropping like these fits a Flood easily.  A Flood with animals alive on exposed surfaces, as BEDS has, would produce dung, and fast burial would preserve it.

Coprolites that were worked by beetles and snails

Other coprolites carry the work of animals that fed on the dung after it was dropped.  In the Two Medicine Formation of Montana, Chin found irregular masses "largely composed of fragmented conifer wood (13%-85%)" that "can be identified as coprolites by the presence of distinctive backfilled dung beetle burrows."³⁴  In the Kaiparowits Formation of southern Utah she and two colleagues found "More than 15 discrete coprolite deposits … within at least three stratigraphic levels in the lower half of the middle unit … at sites up to 20 km apart."⁵  "Open and backfilled burrows are common in the fecal deposits.  …  These fossil burrows resemble the burrowing traces of extant dung beetles which lay eggs in burrows provisioned with dung."⁵  Snail shells are in the dung, and "it is likely that at least some of the gastropods in the coprolites had sheltered and fed within dung pats that were already deposited."⁵

Living dung beetles set the clock.  In Mexican cattle pastures, Carmen Huerta and colleagues report that beetles "removed 40.1 % of the initial weight of the dung pat" within 24 hours, and that "the highest dung removal activity of beetles is presented between 24 and 48 hours of dung exposure, although peaks in activity may occur up to 96 hours after deposition."⁶⁶  With beetles active in the rainy season, pats "in 4 days … had lost 86% of their initial weight, in 1 month they had lost 98% and in 2 months the dung pats had disappeared completely."  In the dry season the same loss "required 2 weeks of exposure."⁶⁶  Elephant dung piles in the Virunga park of Congo, checked every two weeks, lasted on average about 55 days.³⁵

So a coprolite with backfilled beetle burrows lay on the ground for at least a day, and probably for a few days, before it was buried.  Snails living in old dung add more.  That is a surface clock.  It runs on the bedding plane where the dung lies, and in the Kaiparowits it runs on at least three such planes.

This is not a large number.  A day to a few days per surface fits inside the hours or days that Oard's book allows for each exposure.  It is the first trace in this article that has to be spent on the surface itself, in the middle of the Flood year.

The Chañares latrines

The best-studied dung beds are the Triassic latrines of the Chañares Formation in La Rioja, Argentina, described in 2013 by Lucas Fiorelli and seven colleagues.  "The areal density of coprolites is extremely high, averaging 66.6 coprolites/square metre but reaching maximum densities of 94 coprolites/square metre and an estimate of ~30,000 coprolites in the most abundant areas."⁷  "The coprolite fields have variable areal extensions between 400 to 900 square metres and are separated around 1.5 kilometres from each other."⁷  The producers were large dicynodonts, beaked plant-eating relatives of mammals, and the size of the droppings suggests herds made up mostly of juveniles and sub-adults.⁷

The authors argue for fast final burial.  The latrines are "massive autochthonous biogenic accumulations buried in a short-term deposition event," and in the supplement, "It is logical to assume that the thanatocenosis and time-averaging were virtually zero by the rapid mass burial (likely a catastrophic burial) of thousands of associated coprolites at the latrines."⁷⁷  But the dung lay out before that burial.  The coprolites outside concretions, "as usually occurs in the latrines, also show some degree of weathering exposure with cracks and pits, microfracture surfaces, and a few trace fossils … By contrast, coprolites within concretions exhibit no weathering."⁷  Their upper surfaces carry "deep grooves and desiccation cracks, mostly produced by weathering before burial."⁷

Clarey's ICR article reads this the other way round.  It says the authors "suggest that the dung piles were buried rapidly because many of the coprolites exhibit no weathering or bioturbation, e.g., dung beetle or earthworm activity, from long-term exposure."⁸  The unweathered coprolites are the ones sealed in concretions, which the supplement says are the exception in the latrines.  Clarey also gives "an average density of about 80 coprolites per square yard."⁸  That is about 96 per square metre, the paper's maximum, not its average of 66.6.

Clarey's time claim can still be priced.  He says the animals were "surrounded and trapped by rising water for several days."⁸  How long does it take a herd to drop 30,000 droppings on one patch of ground?  The answer is herd size times droppings per animal per day.  No one has measured a dicynodont, so the only measured rates are from living megaherbivores.  Asian elephants in a semi-wild camp averaged 13.5 dung piles a day, and the rate commonly used for wild elephants is 18.³⁶³⁷  Young elephants defecate less often.³⁷

If each coprolite is one dropping, 30,000 coprolites at 13.5 to 18 a day is about 1,700 to 2,200 animal-days.  Three days needs a herd of about 550 to 740 animals using one 400 to 900 m² patch.  Ten days needs about 170 to 220.  If droppings broke into several pieces, divide by the number of pieces.  If dicynodonts defecated less often than elephants, as reptiles with slow guts may, multiply.³⁸

So the count alone does not refute "several days."  A herd of several hundred is large but not absurd for animals that the same paper argues lived in herds.  The weathering is a clock of days too:  dung dries and cracks in days.  One latrine, taken alone, fits Clarey's reading.

Two things remain open.  A latrine is made by animals coming back to the same spot again and again, which is why the authors read the fields as evidence of herds.  Whether frightened animals trapped by rising water would keep that habit is a question about behaviour that no one has tested.  And there are eight such fields, which the authors say cannot be shown to belong to one surface.⁷  If they lie at different levels, each needs its own exposure.

Verdict on coprolites:  the Flood answer holds for droppings buried at once, and is unfinished for dung worked on the surface.  Beetle-worked and weathered dung needs one to several days on each surface where it lies.  That fits inside a single BEDS exposure.  No young-earth writer has yet counted the dung-bearing surfaces in a section, or asked whether the same surfaces also carry tracks, nests and bored carcasses.

Part 4: Bites, healed and unhealed

A tooth mark on a bone can be made in two ways.  A predator bites a living animal, which may escape and heal.  Or a predator or scavenger feeds on a carcass, and the mark never heals.  Healing is the only way to tell them apart:  "postmortem damage cannot be distinguished from intravital occurrences, unless evidence of healing is present."³

Healed bites: months to years, inside a living animal

In 2013 Robert DePalma and four colleagues described two fused tail vertebrae of a hadrosaur from the Hell Creek Formation of South Dakota, with a Tyrannosaurus tooth crown inside them, infected bone, and new bone growing over the tooth.  "This indicates that the prey escaped and lived for some time after the injury."³  They estimated how long from living animals.  "In modern endothermic animals, trauma to bone is followed by signs of insipient bone healing within the first several weeks.  The first macroscopic evidence of bone healing in mammals can be recognized 7–10 d after the injury.  Healing of reptilian bone is much slower … The massive bone reaction in this report suggests survival of the injury for a significant period, perhaps even years."³  And:  "healing rates from modern ectotherms and endotherms suggest that the hadrosaur could have lived from several months to perhaps a number of years after the attack."³

The living numbers behind that estimate are older than the dinosaur paper.  In 1950 J. J. Pritchard and A. J. Ruzicka broke the leg bones of frogs, lizards and rats, left them unsplinted, and killed animals at intervals to see how far repair had gone.  In the rats, and in lizards kept at 32 to 37 °C, "the repair of the rat's tibia and lizard's femur advanced steadily along parallel courses until bony union had been established on the 20th and 31st days respectively."  A rat femur had still not joined in bone at 55 days, and a frog femur at 26 °C not at 70 days.³⁹  In lizards kept at about 18 °C, "even after 40 days the centre of the haematoma was still unorganized and no new bone or cartilage had appeared" in the lizard.³⁹³⁹  So a clean fracture in a warm reptile knits in about a month, and a cold one takes longer than six weeks to start.  A large infected wound with a tooth in it, like the hadrosaur's, takes longer than a clean break.

Healed bites are common.  Caleb Brown, Philip Currie and François Therrien surveyed tooth-strike lesions on tyrannosaur skulls and found that "the overwhelming majority of tooth-strike lesions show extensive healing, we can suggest that these intraspecific contests were generally nonfatal."⁴⁰  A second Allosaurus skeleton with many injuries shows lesions with "unambiguous evidences of healing," one of which "happened long before the animal died."⁴¹

None of this costs the Flood year anything.  The healing ran inside a living animal, and the animal can have been bitten years before the Flood and drowned in it.  Even on Oard's model, where dinosaurs lived on exposed surfaces until about Day 150, a bite in the first weeks could have healed by the time the animal died.  Wood is right that healed bites show attacks on living animals.  They bear on the question of meat-eating before the Fall, which Death Before the Fall argues, and not on the length of the Flood.

Verdict on healed bites:  the Flood answer holds.

Unhealed bites and scavenging: minutes to weeks, on a surface

An unhealed tooth mark on a carcass is made in moments.  BEDS already has the animals that made them:  dinosaurs on an exposed surface "scavenge dead dinosaurs, of which there would have been many."²  A single feeding bout fits easily into the hours or days BEDS allows.

The clock lengthens when the bones show more than a bite.  Garner's Wyoming Edmontosaurus bonebed has carcasses that "lay around just long enough to rot and be scavenged" before burial.²⁰  Brand and Chadwick put the time needed to rot and scatter a skeleton at "several weeks or months."¹⁹  How long a bone takes to weather once it lies bare, and what that means for bonebeds in Flood rock, is argued in Fossil Graveyards.

Verdict on unhealed bites:  the Flood answer holds for the bite itself, which takes moments.  It does not cover the rotting and scattering that often come with it, and the young-earth side's own geologists say those take weeks or months.

Part 5: Bored carcasses and bones

A bite takes moments.  A boring takes as long as the animal that made it needs to grow up inside the food.  Two kinds of animal bore into dead bone and leave fossil traces:  carrion insects on land, and the bone-eating worm Osedax on the seafloor.  Both arrive late, after the soft tissue is gone, and both need weeks.

Carrion beetles in dinosaur bone

Brooks Britt, Rodney Scheetz and Anne Dangerfield described "mandible marks, pits, and shallow bores on cortical bone, and deep, meandering furrows and tunnels (borings) on articular surfaces" on an articulated Camptosaurus skeleton from the Morrison Formation of Wyoming, and compared them with the work of living dermestid beetles.  "Based on extant dermestid behavior, soft tissues were likely absent and the bones were lipid-laden when the traces were made."  The skeleton is not unusual:  "Examination of more than 5,000 bones from the Morrison and Cedar Mountain formations shows insect traces on bone are common but overlooked and that many bones are substantially damaged by insect mining."⁴²⁴²  Eric Roberts, Raymond Rogers and Brady Foreman named hollow chambers cut into dinosaur bone in Madagascar Cubiculum, and surface trails in bone from the Kaiparowits Formation of Utah Osteocallis.  Chambers like Cubiculum "have been reported elsewhere in North America, Asia, Europe, and Africa in bones ranging in age from Jurassic to Pleistocene, and have been interpreted as pupal chambers constructed by carrion beetle larvae."⁴³

Living carrion beetles set the clock, and it is a slow one.  Forensic entomologists who follow the insects on carcasses find that dermestids come last:  "Late arrivers, such as beetle species in the family Dermestidae, invade a copse in the dry stages of decomposition after early colonizing taxa have already left the remains."⁴⁴  Then the beetles have to grow up.  Reared in the laboratory, the hide beetle Dermestes maculatus took "a mean of 89.7 d at 20 degrees C to 36.4 d at 35 degrees C" to develop, and none reached adulthood at 15 °C.¹¹

So a carcass with dermestid borings in it lay exposed while the flesh rotted or dried away, and then for most of a beetle generation, which is a month in tropical heat and three months at 20 °C.  A pupal chamber in bone means a larva finished feeding and pupated there.  That is a minimum of about five weeks, and more likely two to four months.⁴⁵

That is far longer than the "final hours or days" of a BEDS exposure.  It would fit inside the 80 to 150 days Oard allows for all land-animal activity only if a carcass died early, lay on one exposed surface for most of that time, and was buried just before the end.

There is a fair young-earth answer, and it should be stated.  A bone bored by beetles before the Flood and then carried into Flood sediment costs the Flood nothing.  Pre-Flood carcasses would have been lying about in large numbers, and the Flood could have swept them up.  So the test is whether the bored bones were bored where they now lie.  Britt's Camptosaurus is articulated, which makes long transport after the flesh had gone unlikely but not impossible.  No one on either side has gone through the 5,000 Morrison and Cedar Mountain bones to sort bored bones buried in place from bored bones carried in.  Until someone does, this trace is an unpriced cost, not a refutation.

Osedax in Mesozoic marine-reptile bone

Osedax is a worm that lives on the bones of dead whales and other vertebrates on the seafloor.  "Lacking a mouth and gut, Osedax females host heterotrophic bacterial symbionts … in a branching 'root' system that invades the bone to extract organic compounds."¹²  It needs bone that has lain on the bottom long enough for larvae to find it.  In Monterey Bay, William Jones and colleagues set cow bones on the seafloor at four depths.  "Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones."¹²  "Colonization of cow bones at the shallowest site was markedly slower, about 1 year."¹²  A whale carcass passes through a mobile-scavenger stage "lasting months up to 1.5 years" before the later bone-eating stages.⁴⁶

Silvia Danise and Nicholas Higgs reported Osedax borings "from early-Late Cretaceous (approx. 100 Myr) plesiosaur and sea turtle bones" in England:  small round openings leading to chambers inside the bone.¹³¹³  So a plesiosaur bone lay bare on a Cretaceous seafloor for at least the two months Osedax needs to settle, and long enough after that for the worms to grow.

This is the same kind of clock as the beetles, and it has the same escape.  The bones come from the Cambridge Greensand, "whose fossil fauna is mainly reworked from the top of the underlying Late Albian Gault Formation."¹³  A young-earth reader can put the bored bone's two months before the Flood, or early in it on a seafloor that was not yet being buried, and the reworking afterwards.  The seafloor does not dry out, so BEDS has no special difficulty with a carcass lying on the bottom.  What a Flood model needs is a patch of seafloor that received no sediment for two months or more while the Flood was laying down kilometres of it elsewhere.  That is the same question the hardgrounds pose, and no young-earth model has answered it with a number.

Verdict on bored carcasses and bones:  the Flood answer is unfinished.  Insect and Osedax borings need weeks to months of exposure after death, far more than a BEDS exposure is said to last.  The young-earth side has a real escape:  the boring may have happened before the Flood on bones the Flood later carried in.  The test is in the rocks and has not been run.

Part 6: Borings in wood, shell and rock

Shipworms in drifted wood: a trace the Flood supplies

Fossil wood bored by marine clams is called Teredolites.  Simon Kelly and Richard Bromley set its names in 1984.  Short club-shaped borings across the grain, T. clavatus, "are produced today by species of Martesia," a boring clam.  Long borings along the grain, T. longissimus, are the shipworm kind:  "Borings of the teredine ship-worms which include those of Teredo itself, fall within this ichnospecies."  They give the first a range of Jurassic to Recent and the second Cretaceous to Recent.⁴⁷⁴⁷

Living shipworms bore fast.  Eugene Haderlie and J. C. Mellor X-rayed a single shipworm, Bankia setacea, every month for eight months in a fir panel "exposed floating just below the sea surface in Monterey Harbor."  Its burrow was "48 mm long one month after initial detection," 211 mm at three months, 437 mm at six and 797 mm at nine.⁴⁴  Pine blocks 10 by 10 by 50 cm left in the harbour lost 22 to 43% of their wood in six months and 44 to 82% in a year.⁴  The larvae do not have to wait for wood to appear.  In laboratory work on a Chilean shipworm, larvae "swam actively for more than 100 days after fertilisation when wood was not available and metamorphosised around 60 days after fertilisation in the presence of wood."⁴⁸

So a log bored with Teredolites spent weeks to months in seawater.  On Haderlie's rates a shipworm boring a few centimetres long takes weeks, and a log riddled with long T. longissimus takes months.  The short T. clavatus borings are made by a different clam, whose rate was not found for this article.

This is a trace the Flood supplies.  Oard's explanation for coal and amber pictures great mats of floating logs:  "One can easily envision billions of logs floating on the floodwaters after being uprooted in the initial Flood catastrophe."⁴⁹  Shipworm larvae already in the sea would have bored them.  A bored log in Flood rock needs only that the wood floated, or lay on the seafloor, for weeks to months before burial.  The Flood year has that time.  No young-earth writer found for this article has made this argument, but it is a good one.

Two cautions.  In Haderlie's harbour, panels floating at the surface caught one to three shipworms in three months, while submerged panels caught 30 to 156.⁴  Floating wood is bored more slowly than sunken wood.  And Teredolites also occurs in firm peat at the tops of some coal seams, where the question is whether the peat was in place or afloat.  That setting was not examined for this article.

Verdict on shipworm borings in drifted wood:  the Flood answer holds.

Drilled shells

Predatory snails drill round holes in the shells of living clams and snails.  The holes are common in fossil shell beds.  Like a bite, a drill hole is made while the prey is alive, by a predator feeding.  However long the drilling takes, it runs inside the life of the two animals and costs a Flood nothing.  No drilling time was found for this article.  Whether predation existed before the Fall is argued in Death Before the Fall.

Borings in hardgrounds

A hardground is a seafloor that turned to rock while it was still the seafloor, and was then bored by worms and clams and encrusted by oysters and bryozoans.  That is a surface clock:  the floor had to stop receiving sediment, harden, and be colonised by larvae that grew up in place.  Woodmorappe concedes that some hardgrounds "formed in a matter of months during lulls in Flood action."²³  The case for and against reading hardgrounds as long pauses is made in Flat Gaps and Chalk, Limestone, and the Flood, and is not repeated here.  For this article's table, the young-earth side's own minimum per bored hardground is months.

Part 7: What each trace needs from BEDS

The table gathers the minimum time each kind of feeding trace needs, the living analogue that sets it, and where the clock runs.  It is the input for Briefly Exposed Diluvial Sediments, which adds up what every kind of trace fossil asks of Oard's budget.

Positions in the column are given by geological system and stage, which young-earth geologists use for relative order too.  "Life" means the clock ran inside a living animal, and a Flood model can spend it before the Flood.  "Surface" means it ran on the bed where the trace lies, after the dung fell or the animal died, and so inside the Flood year if the bed is Flood rock.  "Water" means it ran in seawater, not on dry ground.

Three things follow for the BEDS sum.

1. Only five rows charge a surface: beetle-worked dung, latrines, unhealed bites with rotting, insect-bored bones, and Osedax bones, plus the hardgrounds argued elsewhere. Gut contents, healed bites, drill holes and shipworm-bored driftwood cost the Flood year nothing on any surface.
2. The surface minimums run from about a day to about two months. Each fits inside 150 days once. Beetle-worked dung fits inside the "final hours or days" Oard's book allows for a single exposure. Insect-bored carcasses and Osedax bones do not: they need a surface left undisturbed for one to two months or more.
3. The two long clocks have a young-earth escape that a count can test. Bones bored before the Flood and carried in cost nothing. The BEDS article needs, for each formation, the number of horizons with dung worked in place, with articulated or in-place bored skeletons, and with tracks and nests, on the same surfaces.

Objections and responses

"A meal in the stomach proves the Flood."  It proves that one animal died soon after eating and was buried before its stomach rotted.  Mainstream paleontologists say the same about Borealopelta, the Na Duong coprolites and the Chañares latrines.  Fast burial of a carcass is a fact about that carcass.  It says nothing about how much time passed between that bed and the next, which is the question a Flood model has to answer.

"A healed bite took months, so the Flood cannot have been one year."  This overreaches, and skeptics should drop it.  The healing ran inside a living animal.  The animal can have been bitten years before the Flood and drowned in it.  A healed wound tells you the animal survived an attack, not when the rock around it was laid down.

"Some coprolites are really concretions, or were washed in by the Flood."  No young-earth source found for this article makes that argument in print.  Paleontologists raise it themselves.  Hunt wrote that "Coprolites are most likely to be confused with concretions," and gave thirteen features for telling them apart, from shape and inclusions to a calcium-phosphate composition.²⁶  The papers relied on here apply such tests.  The Chañares coprolites hold plant fragments and spores, sit in place with smooth undersides marked by the grit they landed on, and include specimens both inside and outside concretions.⁷⁷  The Saskatchewan coprolite's "matrix-supported distribution of bone fragments argues against the possibility that the mass represents regurgitated material or fluvially aggregated bone debris."³³  Transport is a fair question for any one specimen.  It does not touch dung with intact beetle burrows, which would not survive being rolled along a river bed.

"The dung beetles could have worked the dung before the Flood carried it in."  For dung this is weak.  Fresh dung is soft, and a dropping riddled with open and backfilled burrows would fall apart in a current.  Some Kaiparowits coprolites were found weathered out of overbank deposits, so their exact position is uncertain.⁵  But the two found in place sat in fine sediment as discrete masses, and the latrines are in place by every test their authors ran.

"BEDS allows days on each surface, and beetle-worked dung needs only a day or two."  Agreed.  This article finds that one dung-bearing surface fits one BEDS exposure.  The cost comes from adding up surfaces, which this article leaves to Briefly Exposed Diluvial Sediments.

"The latrines took several days, just as Clarey said."  The arithmetic in Part 3 allows it with a herd of several hundred animals per latrine.  But Clarey's article reverses the authors' evidence on weathering, gives their maximum density as an average, and does not mention that the eight fields cannot be shown to be one surface.

"Insect-bored bones are pre-Flood carcasses the Flood swept in."  That is possible, and Part 5 says so.  It makes a prediction:  bored bones should be scattered, worn and mixed with bones from elsewhere, and should not occur on articulated skeletons resting on soils, among nests and tracks.  The articulated, beetle-bored Camptosaurus is the kind of specimen that tests it.  Nobody has done the survey.

"A warm pre-Flood world would make the beetles grow faster."  The five-week minimum already uses the fastest rate in the study, 36 days at 35 °C, the warmest temperature it tested.

"Brand and Chadwick say scavengers in a catastrophe would process carcasses quickly."  Scavengers and predators can strip a carcass in hours.  Dermestids do not come until it has dried, and then they need a month or more to grow.  A crowd of scavengers does not shorten a beetle's life cycle.

"Why not call the borings a refutation of the Flood?"  Because the transport escape is real and untested, and because each boring clock is weeks to months, which a 150-day window can hold once.  A refutation needs the stacked count, in place, and that work has not been done.

Issues and unanswered questions

• Oard's 2011 book was not available. Dinosaur Challenges and Mysteries has "Scavenged Bones" in its subtitle and may treat dung, gut contents or bored bones. It is not on archive.org. This article relies on Oard's shorter papers and on Thomas's review of the book.
• Ste. Marie's 2011 Creation Matters paper, which Wood recommends as a list of fossil evidence for meat-eating before the Flood, is for members only and was not read.
• The latrine arithmetic uses elephant rates. No one has measured how often a herbivorous reptile defecates in a form usable here, and dicynodonts were neither elephants nor lizards. No measured lifespan of a living communal latrine was found.
• Several key papers were read only as abstracts: Chin 2003, Chin 2007, Varricchio 2001, Britt and colleagues 2008, Roberts and colleagues 2007, Richardson and Goff 2001. Chin and Gill's 1996 paper on dung beetles in Two Medicine coprolites was not read. The full texts may hold numbers on how many horizons carry bored bones or beetle-worked dung.
• Whether bored bones were bored in place has not been tested for any formation. The Morrison and Cedar Mountain survey of 5,000 bones gives a frequency, not a position.
• How many feeding-trace surfaces a section holds has not been compiled. The Kaiparowits has at least three dung levels, and the Chañares eight latrine fields of unknown relation. Counting them, section by section, is the work the BEDS article needs.
• The creation.com article on Osedax that a critic quotes could not be located, so its argument is not represented here.

Verdict

Feeding traces split cleanly by where their clock runs.

Where the clock runs inside a living animal, the Flood answer holds.  A meal in the stomach, a hooklet mass built up over a lifetime, a healed bite, a drilled shell:  all of these record time that ended at death, and a Flood model can spend it before the Flood began.  On gut contents the young-earth writers are right in substance.  A stomach still full of food is evidence that the animal was buried fast, and Borealopelta's meal of "the order of hours" is a good example.  Skeptics should stop citing healed bites against a one-year Flood.

Where the clock runs in seawater, the Flood answer holds too.  Shipworm borings in drifted wood need weeks to months afloat or on the seafloor, and a Flood with floating log mats supplies exactly that.

Where the clock runs on a surface, the Flood answer is unfinished.  Dung worked by beetles needs about a day per surface, and probably several.  The Chañares latrines need days with a herd of several hundred.  These fit Oard's BEDS exposures one at a time.  Insect-bored carcasses and Osedax-bored bones need one to two months of undisturbed exposure, longer than any single BEDS exposure is described as lasting, unless the bones were bored before the Flood and carried in.  No young-earth writer has priced any of these.  ICR's one attempt, on the latrines, reversed what its source said about weathering.

None of these traces alone refutes a one-year Flood.  Their cost is in the sum:  how many dung-bearing, carcass-bearing surfaces a section holds, and whether the same surfaces carry tracks and nests too.  That sum is the job of Briefly Exposed Diluvial Sediments, and Part 7 gives it the inputs.

Sources