Eric Shipton yeti snowprint revisited

So odd, so different,
it might just be real. It all started with a photograph by Eric Shipton from decades ago of a single large footprint in the snow of the Himalayan Mountains (Fig. 1). Here I simply added bones based on the apparent primate nature of the trackmaker and included gorilla pedal data for comparison.

Figure 1. Eric Shipton snowprint of Yeti with hypothetical bones and PILs applied. At top is pes of Gorilla. Ice pick for scale.

Figure 1. Eric Shipton snowprint of Yeti with hypothetical bones and PILs applied. At top is pes of Gorilla. Ice pick for scale. The impressions of digits 2 and 3 indicate logical interpretation with toe drag to avoid broken toe /#2 and nussubg toe #3 impression.

Distinct from human tracks,
the big toe of the Himalayan trackmaker is much bigger and does not extend as far as in humans. The tracks is wider than in humans. Digit 2 appears to be shorter than in humans.

Several years ago an expert of yeti and bigfoot, Dr. Jeff Meldrum,
appeared on ‘Joe Rogan Questions Everything’ #2 with Duncan Trussell (audio only, click to listen via YouTube). While Joe and Duncan tried to add levity to the discussion, Dr. Meldrum portrayed the facts as he knew them, keeping speculation to a minimum.

We touched on this subject
about a year ago earlier here.

Bipedal crocodylomorph (or giant pterosaur tracks?) from Korea

Kim et al. 2020 describe
sets of 18-24cm narrow-gauge tetradactyl (four-toed) bipedal tracks from the Early Cretaceous (Aptian?) coast of South Korea they name Batrachopus grandis (Figs. 1, 2) a new ichnospecies. The authors attribute the tracks to a large (3m) crocodylomorph. They also note: “Surprisingly, the trackways appear to represent bipedal progression which is atypical of all known smaller batrachopodid trackways.”

You might find their logic train interesting. (See below.)

By the way, such narrow-gauge tracks (Fig. 2) are also atypical for Cretaceous crocs and azhdarchid pterosaurs, like the Late Cretaceous trackmaker of the ichnospecies, Haenamichnus (Figs. 2, 3).

On the other hand, basalmost Triassic crocs were all narrow-gauge bipeds. None of these were large (but that can change), plantigrade (but that can change) or left tracks (that we know of).

Such narrow-gauge tracks were also typical for strictly bipedal pterosaurs, like the coeval (Early Cretaceous) Shenzhoupterus (Figs. 5–7), a taxon overlooked by Kim et al. 2018, 2020.

Figure 1. Batrachopodus grandis tracks from Kim et al. 2020. Note the digits are shorter than the metatarsals and the heel is half the maximum width of the foot, matching both Early Jurassic Protosuchus and coeval (Early Cretaceous) Shenzhoupterus.

Figure 2. Batrachopus tracks (2nd from left) compared to other croc tracks.

Figure 2. Batrachopodus tracks (2nd from left) compared to other croc tracks. Haenamichnus uhangriensis, azhdarchid quadrupedal pterosaur tracks shown at far right, with three fingered manus track, outside and slightly behind the oval (here at this scale) pedal track.

From the Kim et al. abstract:
“This interpretation helps solve previous confusion over interpretation of enigmatic tracks of bipeds from younger (? Albian) Haman formation sites by showing they are not pterosaurian as previously inferred. Rather, they support the strong consensus that pterosaurs were obligate quadrupeds, not bipeds.”

Consensus = current opinion. What you really want  and deserve is evidence! (…and not to overlook evidence that is already out there). Peters 2000, 2011 showed that many pterosaurs were bipedal. Specific beachcombing clades were quadrupedal secondarily.

Figure 2. The large azhdarchid pterosaur, Zhejiangppterus. is shown walking over large pterosaur tracks matched to its feet from Korea (CNUPH.p9. Haenamichnus. (Hwang et al. 2002.)

Figure 3. The large azhdarchid pterosaur, Zhejiangppterus. is shown walking over large pterosaur tracks matched to its feet from Korea (CNUPH.p9. Haenamichnus. (Hwang et al. 2002.)

Unfortunately,
basal crocodylomorph feet are almost entirely absent from the fossil record in tested taxa in the large reptile tree (LRT, 1697+ taxa). The only exception is bipedal and likely digitigrade, Terrestrisuchus (Fig. 4). We don’t get another complete set of toes for testing until quadrupedal and plantigrade Protosuchus (Fig. 4), a not so basal crocodylomorph, that had the slightly more gracile digit 4 common to all extant crocs. Digit 4 does not appear to be any more gracile than the other toes in the new South Korean tracks, but let’s overlook that trifle for the moment.

Figure 2. Same feet, reordered according to the large reptile tree. Only Terrestrisuchus and Protosuchus are croc-like archosaurs here. Poposaurs are basal dinosaurs.

Figure 4. Same feet, reordered according to the large reptile tree. Only Terrestrisuchus and Protosuchus are croc-like archosaurs here.

Perhaps that is why Kim et al. write:
“Lower Jurassic Batrachopus with foot lengths (FL) in the 2–8 cm range, and Cretaceous Crocodylopodus (FL up to ~9.0 cm) (Fig. 2) known only from Korea and Spain registered narrow gauge trackways indicating semi-terrestrial/terrestrial quadrupedal gaits. Both ichnogenera, from ichnofamily Batrachopodidae, have been attributed to Protosuchus-like semi-terrestrial crocodylomorphs.”

… with a wider-gauge quadrupedal track.

On that note: The type species for Batrachopus is much smaller, fleshy, quadrupedal, narrow-gauge, with pedal impressions just behind the much smaller manus impressions.

By the start of the Cretaceous all the earlier bipedal crocodylomorphs were extinct, according to the current fossil record. Shenzhoupterus, from China, was a nearby contemporary of the South Korean trackmaker with nearly identical feet and gait. Did I hear someone say, “Occam’s Razor“? Did someone mention, “taxon exclusion”?

Earlier Kim et al. 2012 described similar tracks
as pterosaurian. Back then they were matched here to a giant Shenzhoupterus (Figs. 5–7), a coeval (Aptian, Early Cretaceous) dsungaripterid relative found in nearby China, with forelimbs less likely to reach the ground. Later a partial skeleton of a giant Late Cretaceous pterosaur from France, Mistralazhdarcho (Vullo et al. 2018), was reidentified here as a giant shenzhoupterid, rather than an azhdarchid. So shenzhoupterids were not restricted in size.

Kim et al report on, “Distinguishing crocodilian from pterosaurian trackways.”
“An unexpected result of the discovery of B. grandis trackway has been to shed light on a the controversial issue of pterosaur locomotion debated since the 1980 and 1990s: were pterosaurs bipedal or quadrupedal?

The answer is some were bipedal. Others were quadrupedal (Peters 2000, 2011, not cited by Kim et al.). It all depends on the clade and their niche.

Kim et al continue:
“These debates, mainly concerning relatively small pterosaurian tracks, have largely been resolved in favor of quadrupedalism.

Largely? Does that mean Kim et al. recognize exceptions? If so, they were not cited. More importantly, look for any other distinguishing traits in what follows from the Kim et al. text.

Kim et al continue:
“However, some uncertainty remained regarding tracks of purported ‘giant’ pterosaurians that were described as ‘enigmatic’ and inferred to have progressed bipedally (Kim et al. 2012). These trackways from the Lower Cretaceous, Haman Formation, at the Gain-ri tracksite, Korea were named Haenamichnus gainensis and inferred to represent, large, plantigrade pterodactyloid pterosaurs that might have walked bipedally so that the long wings did not become mired in the substrate. It was further inferred they may have been wading in shallow water.”

amples from the Lower Cretaceous, Gain, Korea trackway

Figure 5. Samples from the Lower Cretaceous, Gain, Korea trackway (left) along with original tracings of photos, new color tracings of photos with hypothetical digits added in red, then candidate trackmakers from the monophyletic Shenzhoupterus/Tapejarid clade.

Estimating Gain pterosaur trackmakers from track sizes and matching taxa.

Figure 6. Estimating Gain pterosaur trackmakers from track sizes and matching taxa. Note the Shenzhoupterus manus is a wee bit too short to touch the substrate as in Tupuxuara and many other derived pterosaurs.

Figure 1. Mistralazhdarcho compared to reconstructions of Shenzhoupterus and Nemicolopterus.

Figure 7. Mistralazhdarcho compared to reconstructions of Shenzhoupterus and Nemicolopterus.

Kim et al continue:
“We can now confirm confidently, that these tracks from the Gain-ri tracksite and others from Adu Island: are identical to poorly preserved large Batrachopus trackways. Thus, they should be removed from Haenamichnus and regarded as large poorly preserved batrachopodid tracks. The type specimen then tech- nically becomes Batrachopus gainensis (comb nov.). Thus, H. gainensis becomes a footnote to ichnotaxonomic history, shown to be an extramorphological expressions large of Batrachopus, only recognizable retrospectively after comparison with B. grandis. Therefore ichnologists may retrospectively choose to regard H. gainensis as a nomen dubium, and find little value in the trival name (gainensis). Alternatively they may simply refer to the Haman Formation tracks as Batrachopus cf. grandis.

Taken on its face, this is a rare instance of a paleontologist admitting a mistake. The other option is: both tracks are pterosaurian. So far, as you’ll note, the authors have not pointed to any factors, other than ‘bipedalism’, that would dissuade a pterosaurian trackmaker interpretation. I will admit and you can see (Figs. 4–5) that the pedes of Protosuchus and Shenzoupterus are rather close matches when covered with pads.

Kim et al continue:
“Note that the Gain-ri and Adu island trackways are from the Haman Formation and so these occurrences indicate a widespread distribution in space (three sites) and time (two formations) of this distinctive apparently bipedal morphotype. The pes tracks from the two Haman Formation sites are also larger (27.5–39.0 cm long), but with trackway proportions (step, stride, pace angulation etc.,) quite similar to those from the Jinju Formation.”

“The identification of the Haman Formation trackways as poorly preserved large batrachopodid tracks apparently suggests that the trackmakers habitually progressed bipedally. Alternatively the same speculative arguments for apparent rather than real bipedalism would have to be invoked as was the case with the Jinju material. Moreover, in almost all cases the trackways are very narrow gauge with a narrower straddle than seen in modern crocodylians. It is also of interest that least five subparallel more or less equally spaced trackways were registered on the level 4 surface. This suggests either that the trackmakers may have been gregarious, or that they were following a physically controlled route, such as a shoreline, defined by the paleoenvironment.”

Still no distinguishing traits, other than bipedalism, according to the authors. And note, they never considered the coeval and neighboring pterosaur, Shenzhoupterus, which is also a close match for the new tracks. They chose to invent a croc trackmaker rather than consider a pterosaurian trackmaker, evidently bowing to the consensus (their word, not mine, see above) and to follow Dr. Bennett’s curse and keep their blinders on. I wish they had dived deeper into the literature and evidence instead of following the crowd.


References
Hwang KG, Huh M, Lockley MG, Unwin DM and Wright JL 2002. New pterosaur tracks (Pteraichnidae) from the Late Cretaceous Uhangri Formation, southwestern Korea. Geology Magazine 139(4): 421-435.
Kim, JY et al. 2012. Enigmatic giant pterosaur tracks, and associated ichnofauna from the Cretaceous of Korea: implications for bipedal locomotion of pterosaurs. Ichnos 19, 50–65 (2012).
Kim KS, Lockley MG, Lim JD, Bae SM and Romilio A 2020. Trackway evidence for large bipedal crocodylomorphs from the Cretaceous of Korea. Nature Scientific Reports 10:8680 | https://doi.org/10.1038/s41598-020-66008-7
Lockley, MG et al. 2020. First reports of Crocodylopodus from Asia: implications for the paleoecology of the Lower Cretaceous.Cretaceous Research (2020) (online, March 2020).
Peters D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos, 7: 11-41
Peters D 2011.
A Catalog of Pterosaur Pedes for Trackmaker Identification Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605
Vullo R, Garcia G, Godefroit P, Cincotta A, and Valentin X 2018.
 Mistralazhdarcho maggii, gen. et sp. nov., a new azhdarchid pterosaur from the Upper Cretaceous of southeastern France. Journal of Vertebrate Paleontology. DOI: 10.1080/02724634.2018.1502670.

https://pterosaurheresies.wordpress.com/2012/03/25/giant-bipedal-pterosaur-tracks-from-korea/

https://pterosaurheresies.wordpress.com/2018/10/19/mistralazhdarcho-a-new-pterosaur-but-not-an-azhdarchid/

In memoriam: Professor Jennifer Clack

If you never met her,
here’s your second chance, via YouTube videos.

This week marks the passing of Professor Jennifer Clack (1947-2020),
a renown specialist in Devonian tetrapods, especially Acanthostega (Fig. 1). In the above 4-minute YouTube video from 2017, Clack introduces her concept that the first tetrapods, like her discovery of Acanthostega, had more than five manual digits. This is confirmed by Middle Devonian tetrapod tracks (Fig. 3) with more than five digits.

Figure 4. Acanthostega does not have much of a neck.

Figure 1. Acanthostega does not have much of a neck. Note the narrow torso, taller than wide, distinct from lobefin fish that phylogenetically led to basal tetrapods, like Trypanognathus in figure 4.

But not
according to the large reptile tree (LRT) which recovers Acanthostega as a terminal taxon, not a transitional one, far from the main line of tetrapod origins. Four digits are found in Panderichthys, Greererpeton and many other basal tetrapods, as we learned earlier here, here and here. More than five digits are found in only a few derived taxa, including the stem reptile, Tulerpeton, far from the origin of digits.

A more complete and technical account
of basal tetrapod traits is provided by Clack in this 20-minute YouTube lecture video from 2016 (above).

It may be that Clack only saw evolutionary progress
without considering the possibility of evolutionary reversal, as happens when taxa return to a more aquatic niche from a less aquatic niche, reducing the importance of their digits and limbs. In the above video, Clack does not provide a phylogenetic analysis, like the LRT (subset Fig. 2) that includes more primitive, but late-surviving basal tetrapods, all of which follow the pattern of a wider than deep torso, as in ancestral fish with embedded arm bones in their lobefins. Rather, she concentrates on individual traits, which while valuable, set her up for ‘Pulling a Larry Martin‘, rather than concentrating efforts on determining a phylogeny that minimizes taxon exclusion and lets the software determine (= mirror) evolutionary events, as the LRT does while minimizing taxon inclusion bias.

Figure 4a. Subset of the LRT focusing on basal tetrapods. Note the displaced positions of Acanthostega and Ichthyostega.

Figure 2. Subset of the LRT focusing on basal tetrapods. Note the displaced positions of Acanthostega and Ichthyostega.

Only after a phylogeny is documented and validated
can one then discuss the various traits and their uses by the creature that possessed them.

Lest we forget
the first tetrapod tracks (Fig. 1, Niedźwiedzki et al. 2010) predate fossil tetrapods, including Acanthostega, by 20 to 30 million years, as we looked at here. And even they had more than five toes. Thus the phylogenetic origin of tetrapods goes back even further. The early Devonian must have provided quite a few niches for such rapid evolution to take place.

Figure 3. Best Devonian Valentia track with various overlays.

Figure 3. Best Devonian Valentia track with various overlays.

We need to look more closely at
Trypanognathus (Fig. 4; latest Carboniferous), which is the most primitive, but by far not the earliest, taxon in the LRT to document fingers and limbs, rather than lobe fins. Note the anterior eyes, wide flat skull and body, and primitive sprawling limbs. Can someone count the fingers and toes on this specimen? I find no more than four digits. Some may be hiding here.

Figure 1. Trypanognathus in situ, colorized to bring out ribs and limbs.

Figure 4. Trypanognathus in situ, colorized to bring out ribs and limbs is the most primitive, but not the earliest taxon with limbs and toes, not lobe fins.

We’ve seen the chronology of several fossil finds
at odds with their phylogeny in the LRT (e.g. multituberculates, bats, Gregorius). That keeps it interesting, but only a wide gamut phylogenetic analysis based on traits will deliver a valid tree topology. As time goes by and more discoveries are made the competing hypotheses will someday converge.

Figure 2. Silvanerpeton from the Upper Viséan (331 mya) is the outgroup taxon for Gephyrostegus and the Amniota.

Figure 5. Silvanerpeton from the Upper Viséan (331 mya) is the outgroup taxon for Gephyrostegus and the Amniota.

And one more thing,
Clack 1994 described Silvanerpeton (Fig. 5, Viséan, 335 mya) first as an anthrcosauroid and later (Ruta and Clack 2006) as a stem tetrapod, all without recovering it as the basalmost reptile, as shown in the LRT. Adding taxa, creating a wider gamut phylogenetic analysis, would have brought even more fame to this well-respected paleontologist.


References
Clack JA 1994. Silvanerpeton miripedes, a new anthracosauroid from the Visean of East Kirkton, West Lothian, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences 84 (for 1993), 369–76.
Niedźwiedzki G, Szrek P, Narkiewicz K, Narkiewicz M and Ahlberg PE 2010. Tetrapod trackways from the early Middle Devonian period of Poland Nature 463, 43-48. doi:10.1038/nature08623
Ruta M and Clack, JA 2006 A review of Silvanerpeton miripedes, a stem amniote from the Lower Carboniferous of East Kirkton, West Lothian, Scotland. Transactions of the Royal Society of Edinburgh: Earth Sciences, 97, 31-63.

https://www.zoo.cam.ac.uk/news/professor-jenny-clack-frs-1947-2020

http://www.theclacks.org.uk/jac/Biography.html

https://www.pbs.org/wgbh/nova/link/clack.html
(make sure to click on the parts 2-4 links therein)

 

Mythbusting: Prorotodactylus

We looked at the Early Triassic ichnogenus, Prorotodactylus
(Ptaszynski 2000; Brusatte et al. 2010; Figs. 1,3) earlier here and here.

Today a fresh look
from images published in Brusatte 2018 (Figs. 1, 2, 8), used here for their scientific value, education and criticism.

Figure 1. From Brusatte 2018, colored here. The caption reports, "a handprint overlapping a footprint.' In reality the handprint was put down first, followed by the footprint. Given the presented lighting with shadows below, this is a natural cast of the original impression.

Figure 1. Image rom Brusatte 2018, colored here. The caption reports, “a handprint overlapping a footprint.’ In reality the handprint was put down first, followed by the footprint, as is typical of tetrapods moving forward. Given the presented lighting with shadows below, this is a natural cast of the original impression.

Following Brusatte et al. 2010, Wikipedia reports,
Prorotodactylus is a dinosauromorph ichnogenus known from fossilized footprints found in Poland and France. The prints may have been made by a dinosauromorph that was a precursor to the dinosaurs, possibly closely related to Lagerpeton.” …which is not a dinosauromorph in the LRT, but a dinosaur-mimic related to the gracile and long-legged chañaresuchid, Tropidosuchus (Fig. 3). A wide gamut phylogenetic analysis, like the LRT, has to precede any such mis-pronouncements based on tradition, chasing fame and…

Figure 2. Model of hypothetical trackmaker of Prorotodactylus alongside its creator, paleontologist, Grzegorz Niedzwiedzki (ghosted to bring out the model) from Brusatte 2018.

Figure 2. Model of hypothetical trackmaker of Prorotodactylus alongside its creator, paleontologist, Grzegorz Niedzwiedzki (ghosted to bring out the model) from Brusatte 2018. There is no reason to imagine such a trackmaker when we have a real trackmaker that matches the tracks, Diandognosuchus (Figs. 3,4). Compare this imaginary tetrapod to the real Tropidosuchus (Fig. 3), which lacks digit 5.

Taxon exclusion.
For one reason or another the best matches to Protorotodactylus were excluded to flavor the more exciting headline, “Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic” (Brusatte et al. 2010). Sometimes we have to lose our quest for glory, step back and test all available candidates, lest some amateurs some day pull the curtain back and reveal the error.

Tropidosuchus in its two variants. In the holotype (above) the humerus is more robust and pedal digit 4 is gracile, as in Chanaresuchus (Fig. 3). In the referred specimen of Tropidosuchus (below) the humerus is smaller and pedal digit 4 is longer than 3, as in Lagerpeton. The rise to a bipedal configuration appears to coincide with the change in pedal proportions.

Figure 3. Tropidosuchus in its two variants. In the holotype (above) the humerus is more robust and pedal digit 4 is gracile, as in Chanaresuchus (Fig. 3). In the referred specimen of Tropidosuchus (below) the humerus is smaller and pedal digit 4 is longer than 3, as in Lagerpeton. The rise to a bipedal configuration appears to coincide with the change in pedal proportions.

Figure 3. Manus and pes casts of Prorotodactylus compared to manus and pes of Diandongosuchus (Fig. 4).

Figure 3. Manus and pes casts of Prorotodactylus compared to manus and pes of Diandongosuchus (Fig. 4). Dotted blue line indicates a dragging digit 4 during the recovery phase of the step cycle.

Brusatte 2018 and Brusatte et al. 2010
considered the asymmetric (fourth toe longer than the third) pedal trackmaker of Prorotodactylus an Early Triassic dinosauromorph.

Wikipedia reports,
“Prorotodactylus tracks were probably made by a small dinosauromorph. [not true] The ichnogenus possesses several distinctively archosaurian features, such as narrow trackways and a pace angulation of 130°. [not unique to archosaurs] The pace angulation, or the angle made between two successive footprints, shows that Prorotodactylus had an erect stance rather than a sprawling one. Dinosauromorph [no such clade] characteristics include digitigrade prints (in which only the digits touch the ground), [not unique to this clade] bunched metatarsals, [not true] a reduction of the first and fifth digits, and the posterior deflection of the fifth digit. Prorotodactylus prints share several characteristics [and invalidating characteristics] with the dinosauromorph genus Lagerpeton from Argentina, indicating that the print maker was closely related to Lagerpeton. [bogus conclusion] The three central digits of the foot are parallel, a feature otherwise only seen in Lagerpeton. [not true] Digit IV is the longest digit in the foot of both Prorotodactylus and Lagerpeton. [and most tetrapods] In both animals, there is a progressive decrease in size from digits IV to II, with digit III angled relative to the midline. [not true, Fig. 3] The bunched metatarsals in Prorotodactylus are a synapomorphy of the clade Avemetatarsalia. [invalid clade]. The metatarsal pads, preserved only in deeply imprinted footprints, are united in a single unit. [not true] This makes the foot act as a single unit rather than a collection of splayed digits. [bogus hoopla] In ichnotaxa similar in appearance to Prorotodactylus, the digits are not parallel to one another and the posterior margin of the metatarsal pads is curved, making the digits splay. [not true, consider Cosesaurus].

 

FIgure 2. Diandongosuchus (2012) compares well with Prorotodactylus tracks. These legs are long enough to make overlapping tracks. Diandongosuchus is closer to the genesis of phytosaurs and their sisters, the chañaresuchids than to dinosaurs.

FIgure 4. Diandongosuchus (2012) compares well with Prorotodactylus tracks. These legs are long enough to make overlapping tracks. Diandongosuchus is closer to the genesis of phytosaurs and their sisters, the chañaresuchids than to dinosaurs.

Beside all the above, remember…
Brusatte et al. 2010 and Brusatte 2018 were working from invalid cladograms lacking many key taxa. In their traditional minds, the dinosaur-mimic chañaresuchid, Lagerpeton, was a dinosaur ancestor.

In the large reptile tree (LRT, 1344 taxa) ‘dinosauromorpha‘ is a junior synonym for ‘archosauria’ (birds + crocs + LCA and all descendants). Diandongosuchus (Fig. 4) was published two years after Brusatte et al. 2010. Basal archosauriforms are notoriously  preserved without hands and feet. So, in 2010 there was some excuse.

Figure 5. GIF animation of a very short-legged extant crocodilian demonstrating how the toes nearly touch the wrist during the step cycle. No legs more elongate than Diandongosuchus need to be imagined.

Figure 5. GIF animation of a very short-legged extant crocodilian demonstrating how the toes nearly touch the wrist during the step cycle. No legs more elongate than Diandongosuchus need to be imagined. Despite being a ‘sprawling reptile’ not the erect carriage of the hind limbs.

Wikipedia reports
“Trackways indicate that the maker of Prorotodactylus footprints was quadrupedal. However, the overstep of the hind feet beyond the front feet indicates that the forelimbs were reduced, a characteristic of bipedal animals. [not true]  Another Polish dinosauromorph ichnogenus, Sphingopus, [actually a rauisuchian] occurs later in the Triassic and is fully bipedal. The transition to bipedality probably occurred between Prorotodactylus and Sphingopus. [happened many times in tetrapods}. During this transition, body size also increased, as Sphingopus tracks are larger than those of Prorotodactylus.” [all this guesswork without a wide gamut phylogenetic analysis]

?The different shapes of the manus and pes of Prorotodactylus may show different forms of specialization. [not true] The forelimbs, which were reduced, may have been used for hunting, grasping, or manipulating. [not true]The bunched metatarsals of the hind feet may have enabled the metatarsals to act as a lever, along with the stylopodium, or upper leg, and the zeugopodium, or lower leg. [they nearly always act as a lever in nearly all tetrspods] This would have enabled facultative bipedalism in Prorotodactylus,[confuding an ichnogenus with an undiscovered extinct genus] and a wholly bipedal gait in later dinosauromorphs. [this line of basal archosauriforms is not in dino ancestry] Pace angulation is relatively high in Prorotodactylus, and increased as bipedalism becomes obligate in later dinosauromorphs” [faulty evidence, faulty conclusion]

Phylogenetic analysis can help.

The trackmaker of Prorotodactylus has to have the following traits:

  1. Manus smaller than pes
  2. Quadrupedal
  3. Manus semi-digitigrade, pes fully plantigrade
  4. Neither metacarpus nor metatarsus compact (some radiation)
  5. Hindlimb longer than forelimb
  6. All unguals relatively small, but sharp
  7. Five fingers and five toes
  8. Manual digit 3 is the longest
  9. Pedal digit 4 is the longest
  10. No digits are longer than the metacarpals/metatatarsals
  11. No digits/phlanages are long and gracile.

Distinct from Diandongosuchus,
in the trackmaker of Prorotodactylus:

  1. The manus is relatively longer
  2. The tarsus is not so wide
  3. Manual digit 2 is longer than digit 4
  4. Pedal digit 1 is aligned with the metacarpophalangeal hinge

Some of these problems are fixed
when making comparisons to the manus and pes of Early Triassic ancestor, Proterosuchus (Fig. 6), coeval with Prorotodactylus, but the manus bones are not complete.

Figure 7. The genesis of the Archosauria embodied in PVL 4597 to scale with a modern archosaur, Cyanocitta. Note the longer metatarsals than toes. Pedal digit 5 does not reach the substrate.

Figure 7. The genesis of the Archosauria embodied in PVL 4597 to scale with a modern archosaur, Cyanocitta. Note the longer metatarsals than toes. Pedal digit 5 does not reach the substrate.

What about Sphingopus?
We looked at that large ichnite earlier here. It most closely resembles rauiisuchid pedes because five digits impressed on a digitigrade pes and pedal digit 5 was hooked. This is unlike proximal dino ancestors, like PVL 4597 (Fig. 7). Why do these hypotheses get published without hard evidence and analysis, when we have the hard evidence and analysis?

Synaptichnium

Figure 1. Synaptichnium compared to a slightly altered pes of Proterosuchus. Note a reduction of one phalanx in pedal digit 4 to match one less pad in the ichnite. The last two (or three phalanges) of pedal 4 are unknown in Proterosuchus.

Let’s get real.
Phylogenetic analysis determines which taxa were in the lineage of dinosaurs. You can run an analysis on good ichnites.

We know what the last common ancestor of crocs and birds looked like.
It’s PVL 4597 (Late Middle Triassic; Fig. 7), a bipedal basalmost archosaur originally attributed to Gracilisuchus.

Figure 8. Imagined trackmaker of Prorotodactylus from Brusatte 2018.

Figure 8. Imagined trackmaker of Prorotodactylus from Brusatte 2018. This is wishful thinking, not phylogenetic analysis and bracketing.

Let’s put this Prorotodactylus myth to bed,
or at least attribute it to a basal archosauriform, because it was not impressed by a dinosaur ancestor. Insist that your scientist/authors back up their hypotheses with comprehensive evidence that considers all other possibilities before they set the world on fire with another ‘origin of dinosaurs’ headline that overlooks the validated proximal outgroups. The LRT tests all other candidates, not only at the origin of dinosaurs, but at the origin of reptiles, bats, turtles, snakes, pterosaurs, both types of whales, and every other taxon in the LRT.


References
Brusatte SL, Niedźwiedzki G and Butler RJ 2010. Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic. Proceedings of the Royal Society B. 278 (1708): 1107–1113.
Brusatte S 2018. The rise and fall of the dinosaurs. A new history of a lost world. Wm. Morrow. An imprint of HarperCollins Publishers. 404pp.
Li C, Wu X-C, Zhao L-J, Sato T and Wang LT 2012. A new archosaur (Diapsida, Archosauriformes) from the marine Triassic of China, Journal of Vertebrate Paleontology, 32:5, 1064-1081.
Ptaszynski T 2000. Lower Triassic vertebrate footprints from Wiory, Holy Cross Mountains, Poland. Acta Palaeontologica Polonica45 (2): 151–194.
Stocker MR, Nesbitt SJ, Zhao L-J, Wu X-C and Li C 2016. Mosaic evolution in phytosauria: the origin of longsnouted morphologies based on a complete skeleton of a phytosaur from the Middle Triassic of China. Abstracts of the Society of Vertebtate Paleontology meeting 2016.

https://en.wikipedia.org/wiki/Prorotodactylus

https://pterosaurheresies.wordpress.com/2012/08/29/diandongosuchus-not-a-basal-poposauroid-a-basal-phytosaur/

https://pterosaurheresies.wordpress.com/2016/10/28/you-heard-it-here-first-four-years-ago-diandongosuchus-is-a-stem-phytosaur/

Borehole fossils

In today’s blog post
I’m going to send you to another blog post from “Land of the Dead” here, in which a series of fossils is presented in order of increasing depth in a variety of boreholes around the world. I think you’ll find this, as I did, completely fascinating and well (pun intended) written and well referenced.

Imagine
sinking a plastic drinking straw into mud or sand then withdrawing it to examine the contents. That’s the process, only on a larger scale through solid rock.

Figure 1. Perhaps the most complete vertebrate fossil taken from a borehole, Polysphenodon, a rhynchocephalian from the Triassic discovered at 775m below the surface. From Jaekel 1911, Fraser and Benton 1989

Figure 1. Perhaps the most complete vertebrate fossil taken from a borehole, Polysphenodon, a rhynchocephalian from the Triassic discovered at 775m below the surface. Gray areas were not recovered but imagined based on the position of the known elements. From Jaekel 1911, Fraser and Benton 1989

It’s hit or miss.
Some of the finds are trivial, others are important. Some are terrestrial. Others are marine. Some range back several hundred million years. Others are relatively recent. Some are bones. Others are footprints. All of them are fascinating at the same time, and I just wanted to recommend it.

References
Fraser NC  and Benton MJ 1989. The Triassic reptiles Brachyrhinodon and Polysphenodon and the relationships of the sphenodontids. Zoological Journal of the Linnean Society 96:413-445.
Jaekel O 1911.  Die Wierbeltiere.  Eine Übersicht über diefossilen und lebenden Formen.Borntraeger , Berlin, 252p

Land of the Dead website link

Upper Jurassic Digitrade Pterosaur Track with a Temporal Surprise

Here’s a manus and digitigrade pes pterosaur track (Lockley et al. 2008) that has gone unheralded since its publication. Moreover, it wasn’t originally labeled as a digitigrade track, despite the lack of metatarsal impressions.

And that’s not even the biggest (possible) news, IMHO. The trackmaker appears to have been a tiny Eudimorphodon (Fig. 1) in the Late Jurassic, long after the Late Triassic when Eudimorphodon bones are found. Yesterday we looked at a very large Eudimorphodon-like trackmaker from the Late Triassic.

Changchengopterus, a tiny pterosaur directly derived from eudimorphodontids, was not too different and it lived during the Middle Jurassic. And all non-dimorphodontid pterosaurs were derived from tiny pterosaurs like Changchengopterus, so finding such a pes in Late Jurassic sediments is not too far from our present concepts.

Figure 1. Digitigrade pterosaur track from Upper Jurassic, Colorado. Lockley et al. 2008. Best match is to Eudimorphodon, which has not been found beyond the Triassic otherwise. Note pedal digit 4 is slightly longer than 2 and 3.

Figure 1. Digitigrade left pterosaur track from Upper Jurassic, Colorado (CM 81961). Lockley et al. 2008. Best match, believe it or not, is to Eudimorphodon cromptonellus, which has not been found beyond the Triassic otherwise. But then, pterosaur fossils are very rare in Late Jurassic North America. The trackmaker would have been 3x larger than this tiny specimen. Note pedal digit 4 is slightly longer than 2 and 3. PILs are added to a L-R flipped tracing (upper right) for consistency with the reconstruction (lower left). Despite the differences, no Jurassic pterosaur matches this track this well. Blue = manus. Pink = pes digits 1-4. Green = pes digit 5. The trackmaker would be at least 2.5 times larger than E. cromptonellus. Note how a straight pedal 5.2 can make two impressions at either tip.

It’s common knowledge
among traditional pterosaur workers that all pterosaurs were flat-footed (plantigrade). So, I’m not sure why this track, UCM 81961, which is clearly digitigrade, has not been celebrated lo these past 5 years. Two years ago Peters 2011 matched several enigmatic tracks to various digitigrade pterosaurs, mostly anurognathids. Sorry I missed this one (Fig. 1) prior to that publication.

One Late Jurassic possibility opens other possibilities
The variety of Rhamphorhynchus tracks includes one that has a similar morphology, JME-SOS 4009 (no. 62 in the Wellnhofer catalog). The difference here between the bones and the track is the length of p5.2, and the presence of shorter phalanges p3.2, p4.2 and p4.3, which are not reflected in the UCM track. But the UCM track and no. 62 were contemporaneous. So, it’s a toss up if you allow the possibility of an unknown Rhamphorhynchus with such pedal proportions. At this point, a sister to either trackmaker could be responsible for making the track.

Unique among Rhamphorhynchus specimens, Rhamphorhynchus muensteri (Wellnhofer 1975) JME-SOS 4009, no. 62 in the Wellnhofer catalog has a long digit 4.

Unique among Rhamphorhynchus specimens, Rhamphorhynchus muensteri (Wellnhofer 1975) JME-SOS 4009, no. 62 in the Wellnhofer catalog has a long digit 4.

Heresies can have validity. 
Why was this pterosaur track not identified as digitigrade? I hope workers aren’t ignoring data that goes against their pet hypotheses. That’s why we’re all here, helping each other come to a greater understanding by noticing data and busting paradigms with facts and new ideas.

References
Jenkins FA Jr, Shubin NH, Gatesy SM and Padian K 1999. A primitive pterosaur of Late Triassic age from Greenland. Journal of the Society of Vertebrate Paleontology 19(3): 56A.
Jenkins FA Jr, Shubin NH, Gatesy SM and Padian K 1999. A diminutive pterosaur (Pterosauria: Eudimorphodontidae) from the Greenlandic Triassic. Bulletin of the Museum of Comparative Zoology, Harvard University 155(9): 487-506.
Lockley M, Harris JD and Mitchell L 2008. A global overview of pterosaur ichnology: tracksite distribution in space and time. Zitteliana B28: 185-198.pdf
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification, Ichnos, 18: 2, 114-141.
Wellnhofer P 1975a-c. Teil I. Die Rhamphorhynchoidea (Pterosauria) der Oberjura-Plattenkalke Süddeutschlands. Allgemeine Skelettmorphologie. Paleontographica A 148: 1-33.Teil II. Systematische Beschreibung. Paleontographica A 148: 132-186. Teil III. Paläokolgie und Stammesgeschichte. Palaeontographica 149: 1-30.

wiki/Eudimorphodon
wiki/Rhamphorhynchus

A large bipedal digitigrade Triassic pterosaur: evidence from footprints

Figure 1. Unnumbered and unnamed three-toed Late Triassic track (Conrad et al. 1987) here matched to the pes of a tiny, short-legged Triassic Eudimorphodon scaled up to match the tracks. Also shown is a long-legged pterosaur with relatively small feet, Austriadactylus.

Figure 1. Click to enlarge. (Along the bottom) Unnumbered and unnamed three-toed Late Triassic track (Conrad et al. 1987) here matched to the pes of a tiny, short-legged Triassic Eudimorphodon scaled up to match the tracks. Also shown to scale and to match tracks is a long-legged pterosaur, Austriadactylus, with relatively small feet, but the toes don’t match quite so well. Note: pedal digit 1 is short and so does not impress in this configuration with elevated proximal phalanges. This may represent a running track as only the distal phalanges impress.

Conrad et al. (1987)
illustrated an unnumbered and unnamed bipedal, digitigrade track with a stride length of one meter and the distance from the midline 3x the track width.

The only pedal match
I can come up with is to a tiny, possible juvenile, pterosaur Eudimorphodon cromptonellus, which had a short digit 1, a long digit 4 and an elevated proximal set of phalanges. It’s a good match only if the pterosaur was quite a bit larger (Fig. 2). Digit 5 was held hyper-flexed, off the substrate (Fig. 1). Digit 1 did not impress.

No archosauriform
and no bipedal archosauriform of the Late Triassic had sub-equal digits 2-4. E. cromptonellus has been described as diminutive and a possible juvenile or hatchling. If a hatchling, the 8x larger adult would still be half the size of the hypothetical trackmaker (Fig. 2).

Figure 2. If Eudimorphodon cromptonellus is a hatchling, then an 8x larger adult is only half the size of the hypothetical trackmaker.

Figure 2. Click to enlarge. If Eudimorphodon cromptonellus is a hatchling, then an 8x larger adult is only half the size of the hypothetical trackmaker.

A first
This would represent the first instance of a eudimorphodontid pterosaur in western North America. The large size is interesting because one anurognathid pterosaur known from western North America, Dimorphodon? weintraubi, is also much larger than European and Asian anurognathids. The other anurognatid, Mesadactylus, is more typical in size. An Asian anurognathid, currently represented by the IVPP embryo, is also 8x larger than European and Asian anurognathids. We learned earlier that size increase and decrease is a hallmark of pterosaur evolution.

Bipedal and digitigrade
These tracks, if indeed pterosaurian, confirm the origin hypothesis of Peters (2000a, b) as derived from bipedal and digitigrade fenestrasaur ancestors with elevated proximal phalanges and confirms the same for basal pterosaurs. The slight lateral angle of the digits and the width of the track confirms the lepidosaur/tritosaur ancestry of this ichnotaxon, provided with a splayed lepidosaurian femur.

Sorry
I didn’t consider or recognize this specimen in Peters (2011), the catalog of pterosaur pedes for trackmaker identification. This would have added to other digitigrade pterosaur tracks, most matched to anurognathids.

References
Conrad K, Lockley MG and Prince NK 1987. Triassic and Jurassic vertebrate-dominated trace fossil assemblages of the Cimarron Valley Region: Implications for paleoecology and biostratigraphy. New Mexico Geological Society Guidebook. 38th Field Conference, Northeastern New Mexico 1987. 127-138.
Jenkins FA Jr, Shubin NH, Gatesy SM and Padian K 1999. A primitive pterosaur of Late Triassic age from Greenland. Journal of the Society of Vertebrate Paleontology 19(3): 56A.
Jenkins FA Jr, Shubin NH, Gatesy SM and Padian K 1999. A diminutive pterosaur (Pterosauria: Eudimorphodontidae) from the Greenlandic Triassic. Bulletin of the Museum of Comparative Zoology, Harvard University 155(9): 487-506.
Peters, D 2000a. Description and Interpretation of Interphalangeal Lines in Tetrapods. Ichnos, 7: 11-41.
Peters, D 2000b. A redescription of four prolacertiform genera and implications for pterosaur phylogenesis. Rivista Italiana di Paleontologia e Stratigrafia 106: 293-336.
Peters D 2011. A Catalog of Pterosaur Pedes for Trackmaker Identification
Ichnos 18(2):114-141. http://dx.doi.org/10.1080/10420940.2011.573605

wiki/Eudimorphodon

What about those really BIG Rotodactylus tracks?

While virtually all Rotodactylus (Peabody 1948) tracks (digitigrade, proximal phalanges elevated, long stride, narrow gauge manus / wider pes, occasionally bipedal, first digit impresses at tip only, fifth digit impresses far behind the others, extremely variable speed) are the right shape to fit the Cosesaurus  (Ellenberger and Villalta 1974) pes, as we learned earlier here, some Rotodactylus tracks are BIG (4-5 cm length)! That’s way too big for Cosesaurus to fill. So the search is on for something like Cosesaurus, but far bigger and wide ranging (Fig. 1). Rotodactylus tracks have been found across Europe and the western USA and they range across the Early to Middle Triassic.

Figure 1. Scaling a quadrupedal Cosesaurus to the larger Rotodactylus tracks from Haubold 1983.  Quadrant represents center of balance in the closeup foot. Graphic representation of a butt joint is nearby.

Figure 1. Click to enlarge. Scaling a quadrupedal Cosesaurus to the larger Rotodactylus tracks from Haubold 1983. Quadrant represents center of balance in the closeup foot showing how pedal digit 5 made those posterior impressions with a claw mark (Peters 2000). Graphic representation of a butt joint is nearby. The actual Cosesaurus is much smaller than these trackmakers. I enlarged the coracoid on the larger hypothetical trackmakers because they were not bipedal flappers. This configuration of pedal digit 5 is often preserved in basal pterosaurs.

So, after touting the perfect match of Cosesaurus to Rotodactylus tracks (Peters 2000), this is the first time I’ve conformed Cosesaurus to a quadrupedal pose to match these much larger tracks from the Early (=Lower) Triassic (Solling and Röt formations. Scythian/Anisian) of Germany. Haubold (1983) likened Lagosuchus (Maraschus), but  that’s not as good a match as Cosesaurus and Langobardisaurus, which were not so well known or described in the early ’80s.

So, Rotodactylus tracks are not archosaurian, but proto-pterosaurian, fenestrasaurian.

Cosesaurus matched to Rotodactylus from Peters 2000.

Figuure2. Cosesaurus matched to Rotodactylus from Peters 2000.

Haubold listed 4 points that were significant in the development of archosaurs:

  1. “Reduction of the manus as [a] function of bipedalism;
  2. Stride length in relation to width of trackway and pace angulation (small trackway pattern) as a function of semierect to erect gait;
  3. Reduction of pes digits 1 and 5 as a function of tridactylism (this point is unique in Rotodactylus, which impresses  digit 5 far behind the others).
  4. The cross axis of the pes and the outward orientation of the pes axis to the direction of movement. A more rectangular cross axis may demand a mesotarsal joint.”
Cosesaurus and Rotodactylus, a perfect match.

Figure 3. Click to enlarge. Cosesaurus and Rotodactylus, a perfect match. Elevate the proximal phalanges along with the metatarsus, bend back digit 5 and Cosesaurus (left) fits perfectly into Rotodactylus (right).

Rotodactylus tracks show extreme speed variation, which is rare for reptiles, but compliments the higher metabolic niche of fenestrasaurs.

By assigning Rotodactylus tracks to basal bipedal archosaurs, Haubold made the same hopeful mistake that Brusatte et al. (2011) and Niedzwiedzki et al. (2013) made assigning Rotodactylus tracks to  Lagerpeton. These workers hoped it was transitional to dinosaurs, but the match was poor, both phylogenetically and morphologically. The better match is between Cosesaurus and Rotodactylus (Peters 2000, Fig. 3).

So, what about those really BIG Rotodactylus tracks? They were made my really big mostly quadrupedal cosesaurs, evidently. And evidently, only the little cosesaurus were better bipeds, capable of flapping.

Figure 4. Rotodactylus from Haubold adapted from Peabody 1948. Unfortunately, no reptiles have a rotated and reversed pedal digit 5. But note the resemblance of the conjectural trackmaker to Cosesaurus, unknown in 1948.

Figure 4. Rotodactylus from Haubold 1983 adapted from Peabody 1948. Unfortunately, no reptiles have a rotated and reversed pedal digit 5. But note the resemblance of the conjectural trackmaker to Cosesaurus, unknown in 1948. Note: most reptiles while moving do not have all four limbs on the  ground at one time. The elongated pedal digit 5 shown here is likely a drag mark. Size of these prints: between 4 and 5 cm in length, about the size of the examples in figure 1. Note, no claw marks on pedal digit 5.

So, widespread Rotodactylus tracks demonstrate that cosesaurs were widespread. They also appeared in a variety of sizes. While the large ones remained quadrupedal, like ancestral macrocnemids, the small ones became increasingly bipedal. This radiation of tritosaur lizards preceded the radiation of squamates in the Jurassic and later epochs.

References
Brusatte SL, Niedz´wiedzki G and Butler RJ 2011. Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic. Proceedings of the Royal Society B, 278, 1107–1113.
Ellenberger P and de Villalta JF 1974. 
Sur la presence d’un ancêtre probable des oiseaux dans le Muschelkalk supérieure de Catalogne (Espagne). Note preliminaire. Acta Geologica Hispanica 9, 162-168.
Haubold H 1983. Archosaur evidence in the Buntsandstein (Lower Triassic). Second Symposium on Mesozoic Terrestrial Ecosystems, Jadwisin 1981. Acta Palaeontologica Polonica 28 (1-2):123-132.
Niedzwiedzki G, Brusatte SL and Butler RJ 2013. Prorotodactylus and Rotodactylus tracks: an ichnological record of dinosauromorphs from the Early–Middle Triassic of Poland. Geological Society, London, Special Publications, first published April 23, 2013. doi 10.1144/SP379.12
Peabody FE 1948.
  Reptile and amphibian trackways from the Lower Triassic Moenkopi formation of Arizona and Utah.  University of California Publications, Bulletin of the  Department of Geological Sciences 27: 295-468.
Peters D 2000. Description and Interpretation of Interphalangeal Lines in Tetrapods.  Ichnos 7:11-41.
wiki/Cosesaurus

Cynodontipus – a “hairy paw” from the Middle Triassic?

Dr. Paul Ellenberger will go down in history for his work on Cosesaurus, but his passion was fossil footprints. One impression he considered was this purported “hairy paw” from the Middle Triassic of France. Ellenberger (1976) named it Cynodontipus (Fig. 1). Each “toe” was about 2 inches (5 cm) in width.

Cynodontipus in situ, a partial hairy paw print.

Figure 1. Cynodontipus in situ, a partial purported hairy paw print. This is an excellent print, but difficult to interpret. The hair seems misplaced and anachronistic. The wide toes are odd. So is the lack of ungual imprints.

Ellenberger (1976) interpreted his fossil this way (Fig. 2).

Ellenberger's interpretation of Cynodontipus.

Figure 2. Ellenberger’s interpretation of Cynodontipus.

Hairy pads are not known even in modern arctic mammals, so why should we expect hairy pads in Triassic cynodonts? Especially when one can’t differentiate the pads?? There’s no match for this foot among known Triassic taxa. Perhaps there is another explanation for this enigma.

 

Figure 3. Cynodontipus burrows, likely from a procolophonid. Each color represents a new burrow direction from a central origin.

Figure 3. Cynodontipus burrows, likely from a procolophonid. Each color represents a new burrow direction from a central origin.

So what is it?
When we consider the “hair,” we are drawn to the therapsids as possible candidates, as Ellenberger surmised. But this fossil demonstrates way more hair than can be expected at such an early date. Even in mammals the hands and feet are the last parts to get hairy, and usually pads are plain to see, so this fossil just doesn’t fit several typical ichnite patterns.

Luckily there’s Olsen’s 2012 take on it.
Olsen 2012 wrote: In addition to its type locality in the Middle Triassic of France, Cynodontipus has been identified from the Middle Triassic of Germany, the Middle and Late Triassic of Morocco, the Late Triassic of Nova Scotia, Canada, and the Late Triassic of Connecticut, USA. This last occurrence consists of unlabeled part and counterpart slabs discovered in the Hitchcock collection at the Beneski Museum of Natural History at Amherst College. These specimens show that Cynodontipus is a vertebrate burrow that terminates at a recalcitrant subsurface bedding interface and is not a footprint. The simplest hypothesis of the trace maker of Cynodontipus is that it was a produced by burrowing procolophonids, which are know from the same deposits, are the right size, and are known to have burrowed.

Thus the lines that Ellenberger considered hairs must be tunnel scratch marks instead. Doesn’t that make more sense?

The key take away on this
Even experts can have different opinions on the same fossil. More data appears to clarify enigmas. That’s the progress of Science and that’s what makes this paleo study so fascinating. No one need vilify Ellenberger for his misinterpretation. Likewise, no one need denigrate the results published in reptileevolution.com or here at pterosaurheresies, even if and when results are shown to be in error. Errors need to be corrected, but never by blackwashing an entire output. DN and MW, I hope you’re listening. Olsen (2012) handled Ellenberger’s error very well indeed. We should all take note. Be specific and back up your corrections with evidence.

References
Ellenberger P 1976. Une piste avec traces de soies épaisses dans le Trias inférieur a moyen de Lodéve (Hérault, France): Cynodontipus poythrix nov. gen. nov. sp. les cynodontes in France. Géobios 9(6)769-787.
Olsen PE. 2012.
Cynodontipus: A procolophonid burrow – not a hairy cynodont track (Middle-Late Triassic: Europe, Morocco, Eastern North America. Geological Society of America Abstracts with Programs, Vol. 44, No. 2, p. 92.
Olsen PE, Et-Touhami, M, Whiteside, JH, 2013 (in prep). Cynodontipus Ellenberger is a vertebrate burrow, not a hairy synapsid track. for Journal of Vertebrate Paleontology.