SVP 2018: Large biped in the Permian

Shelton, Wings, Martens, Sumida and Berman 2018 report,
from the same quarry that produced bipedal Eudibamus, comes a MUCH larger taxon most closely comparable to Eudibamus (Fig. 1) with long bones 10 to 24 cm in length. They report, “Given this evidence, we hypothesize that either there was an additional bipedal species that existed sypatrically with E. cursori, or these bone casts represent a later ontogenetic stage of Eudibamus with the type specimen being a juvenile.”

FIgure 1. Eudibamus scaled to femoral (=long bone) lengths of 10 and 24 cm. This makes the giant eudibamid either half a meter or a meter in snout-vent length.

FIgure 1. Eudibamus scaled to femoral (= long bone) lengths of 10 and 24 cm. This makes the giant eudibamid either half a meter or a meter in snout-vent length.

None of the present sisters
to Eudibamus (Fig. 2) in the LRT approach the size of the new bone cast specimen.

Figure 1. Basal diasids and proto-diapsids. Largely ignored these putative synapsids actually split from other synapsids while retaining the temporal fenestra trait that serves as the basis for the addition of upper temporal fenestra in diapsids. Included here are Protorothyris, Archaeovenator, Mycterosaurus, Heleosaurus, Mesenosaurus, Broomia, Milleropsis, Eudibamus, Petrolacosaurus, Spinoaequalis, and Tangasaurus.

Figure 2. Basal diasids and proto-diapsids. Largely ignored these putative synapsids actually split from other synapsids while retaining the temporal fenestra trait that serves as the basis for the addition of upper temporal fenestra in diapsids. Included here are Protorothyris, Archaeovenator, Mycterosaurus, Heleosaurus, Mesenosaurus, Broomia, Milleropsis, Eudibamus, Petrolacosaurus, Spinoaequalis, and Tangasaurus.

The authors continue to hold to their original hypothesis
that Eudibamus is a bolosaurid (Fig. 3). In the large reptile tree (LRT, 1313 taxa) bolosaurids nest with diadectids and procolophonids. Eudibamus nests with basalmost diapsids (Fig. 3).

Figure 2. Eudibamus skull revised here with new data compared to bolosaurids, on the left, and basal diapsids, on the right. Post crania for bolosaurids is very fragmentary. Bolosaurids are related to pareiasaurs and turtles, all derived from millerettids. Can you see why Eudibamus was confused with bolosaurids?

Figure 2. Eudibamus skull revised here with new data compared to bolosaurids, on the left, and basal diapsids, on the right. Post crania for bolosaurids is very fragmentary. Bolosaurids are related to pareiasaurs and turtles, all derived from millerettids. Can you see why Eudibamus was confused with bolosaurids?

It will be interesting to see
what this new Early Permian taxon looks like when it becomes available. Right now it is an outlier.

References
Shelton CD, Wings O, Martens T, Sumida SS and Berman DS 2018. Evidence of a large bipedal tetrapod from the Early Permian Tambach Formation preserved as natural bone casts discovered at the Bromacher quarry (Thuringia, Germany). SVP abstracts.

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Giant rat (Coryphomys), giant squirrel (Ratufa) and giant capybara (Josephoartigasia)

Another short one today.
The images say it all.

Figure 1. The giant rat (genus: Coryphomys) compared to an extant rat of typical size.

Figure 1. The giant rat (genus: Coryphomys) compared to an extant rat of typical size.

Some rodents grew really big
(by comparison to their modern counterparts). We have a giant rat (genus: Coryphomys, Fig. 1) and a giant capybara (genus: Josephoartigasia, Fig. 2; Rinderknecht & Blanco 2008), the size of a cow. The largest living rodent is the capybara (genus: Hydrochoerus). One might say it is the size of a pig with a skull larger than a human skull.

Figure 9. Josephoartigasia monesi dwarfs the largest extant rodent, Hydrochoerus, the capybara.

Figure 2. Josephoartigasia monesi dwarfs the largest extant rodent, Hydrochoerus, the capybara. That skull is 53cm long.

The giant squirrel,
Ratufa (Fig. 3; extant) at 36 cm snout/vent length is the size of a small dog.

Figure 2. Ratufa, giant Indian squirrel skeleton and in vivo image. Note the large, cat-like claws and compare them to the smaller claws on all related taxa.

Figure 2. Ratufa, giant Indian squirrel skeleton and in vivo image. Note the large, cat-like claws and compare them to the smaller claws on all related taxa.

References
Aplin et al. 2010. Quaternary Murid Rodents of Timor Part I: New Material of Coryphomys buehleri Schaub, 1937, and Description of a Second Species of the Genus. Bulletin of the American Museum of Natural History, 2010; 3411 DOI: 10.1206/692.1
Aplin KP and Helgen KM 2010. Quaternary murid rodents of Timor part I: new material of Coryphomys buehleri Schaub, 1937, and description of a second species of the genus. Bulletin of the American Museum of Natural History. 341: 1–80. doi:10.1206/692.1
Braun J, Mares M, Coyner B and Van Den Bussche R 2010. New species of Akodon (Rodentia: Cricetidae: Sigmodontinae) from central Argentina. Journal of Mammalogy, 91 (2), 387-400 DOI: 10.1644/09-MAMM-A-048.1
CSIRO Australia. Archaeologists discover biggest rat that ever lived: Weight of about 6 kilograms (over 13 lb). ScienceDaily. ScienceDaily, 26 July 2010.
Rinderknecht A, Blanco RE 2008. “The largest fossil rodent”. Proceedings of the Royal Society B. 275 (1637): 923–8.

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

Big pterosaurs: big or little wing tips

Earlier and below (Fig. 2) we looked at large and giant pterosaur wings comparing them to the largest flying birds, including one of the largest extant flying birds, the stork, Ciconia, and the extinct sheerwater, Pelagornis, the largest bird that ever flew.

FIgure 2. A basal pteranodotid, the most complete Pteranodon, the largest Pteranodon skull matched to the largest Pteranodon post-crania compared to the stork Ciconia and the most complete and the largest Quetzalcoatlus

FIgure 1. A basal pteranodotid, the most complete Pteranodon, the largest Pteranodon skull matched to the largest Pteranodon post-crania compared to the stork Ciconia and the most complete and the largest Quetzalcoatlus. Note the much reduced distal phalanges in the complete and giant Quetzalcoatlus, distinct from the Pteranodon species.

Today
we’ll look at how the largest Pteranodon (Figs. 1, 4) compares to much larger pterosaurs, like Quetzalcoatlus northropi (Figs. 1, 2) that have vestigial wingtips similar to those of the  much smaller flightless pre-azhdarchid, SOS 2428 (Fig. 3).

Note the tiny three distal phalanges
on the wing of the largest Quetzalcoatlus, distinct from the more typical elongate and robust distal phalangeal proportions on volant pterosaurs of all sizes. Much smaller definitely flightless pterosaurs, like SOS 2428, shrink those distal phalanges, too. That’s the pattern when pterosaurs lose the ability to fly.

Figure 2. Q. northropi and Q. sp. compared to Ciconia, the stork, and Pelagornis, the extinct gannet, to scale. That long neck and large skull of Quetzalcoatlus would appear to make it top heavy relative to the volant stork, despite the longer wingspan. Pteranodon and other flying pterosaurs do not have such a large skull at the end of such a long neck (Fig. 1). The longer wings of pelagornis show what is typical for a giant volant tetrapod, and Q. sp. comes up short in comparison.

Figure 2. A previously published GIF animation. Q. northropi and Q. sp. compared to Ciconia, the stork, and Pelagornis, the extinct gannet, to scale. That long neck and large skull of Quetzalcoatlus would appear to make it top heavy relative to the volant stork, despite the longer wingspan. Pteranodon and other flying pterosaurs do not have such a large skull at the end of such a long neck (Fig. 1). The longer wings of pelagornis show what is typical for a giant volant tetrapod, and Q. sp. comes up short in comparison.Today we’ll compare the wingspan of the largest Quetzalcoatlus to the largest and more typical Pteranodon species (Fig. 2).

Unfortunately
pterosaur workers refuse to consider taxa known to be flightless, like SOS 2428 (Peters 2018). It’s easy to see why they would be flightless (Fig. 3). Scaled to similar snout/vent lengths with a fully volant pterosaur like n42 (BSPG 1911 I 31) the wing length and chord are both much smaller in the flightless form.

Lateral, ventral and dorsal views of SoS 2428

Figure 3. Lateral, ventral and dorsal views of the flightless SoS 2428 (Peters 2018) alongside No. 42, a volant sister taxon.

Comparing the largest ornithocheirid,
SMNK PAL 1136, to the largest Pteranodon (chimaera of largest skull with largest post-crania in Fig. 4) shows that large flyers have elongate distal phalanges, distinct from body and wing proportions documented in the largest azhdarchids, like Quetzalcoatlus.

Figure 5. Largest Pteranodon to scale with largest ornithocheirid, SMNS PAL 1136.

Figure 4. Largest Pteranodon to scale with largest ornithocheirid, SMNS PAL 1136. Note the long distant wing phalanges on both of these giant flyers. This is what pterosaurs evolve to if they want to continue flying. And this is how big they can get and still fly. Giant azhdarchids exceed all the parameters without having elongate wings. Note: the one on the left has a longer wingspan whir the one on the right has a more massive torso and skull together with more massive proximal wing bones and pectoral girdle. On both the free fingers are tiny, parallel oriented laterally and slightly tucked beneath the big knuckle of the wing finger. The pteroid points directly at the deltopectoral crest. 

As the largest Pteranodon and largest ornithocheirid (SMNS PAL 1136)
(Fig. 4) demonstrate, as flying pterosaurs get larger, they retain elongate distal wing phalanges. And big, robust phalanges they are.

By contrast in azhdarchids and pre-azhdarchids
there is a large size bump after n42 (BSPG 1911 I 31) the fourth wing phalanx either disappears (see Microtuban and Jidapterus) or shrinks to a vestige. Then there’s Zhejiangopterus (Fig. 5), with a big pelvis, gracile forelimbs and a giant skull on a very long neck. Just that neck alone creates such a long lever arm that the pterosaur is incapable of maintaining a center of balance over or near the shoulder joints.

Figure 1. Click to enlarge. There are several specimens of Zhejiangopterus. The two pictured in figure 2 are the two smallest above at left. Also shown is a hypothetical hatchling, 1/8 the size of the largest specimen.

Figure 5. There are several specimens of Zhejiangopterus. The two pictured in figure 2 are the two smallest above at left. Also shown is a hypothetical hatchling, 1/8 the size of the largest specimen.

As mentioned earlier, becoming flightless permitted, nay, freed azhdarchid pterosaurs to attain great size. They no longer had to maintain proportions that were flightworthy. Instead they used their shortened strut-like forelimbs to maintain a stable platform in deeper waters. And when they had to move in a hurry, their wings could still provide a tremendous amount of flurry and thrust (Fig. 6) for a speedy getaway.

Quetzalcoatlus running like a lizard prior to takeoff.

Figure 6. Quetzalcoatlus running without taking off, using all four limbs for thrust. That long lever arm extending to the snout tip in front of the center of gravity is not balanced in back of what would be the center of lift over the wings

For the nitpickers out there…
some specimens of Nyctosaurus (UNSM 93000, Fig. 7) also have but three wing phalanges, but they are all robust. The distal one is likely the fourth one because it remains curved. Phalanges 2 and 3 appear to have merged, or one of those was lost. Compare that specimen to a more primitive Nyctosaurus FHSM VP 2148 with four robust wing phalanges.

Figure 5. Cast of the UNSM 93000 specimen of Nyctosaurus. Missing parts are modeled here.

Figure 5. Cast of the UNSM 93000 specimen of Nyctosaurus. Missing parts are modeled here.

References
Peters D 2018. First flightless pterosaur (not peer-reviewed). PDF online.

 

Mammal taxa: size categories

A few days ago, we looked at a revised and expanded cladogram of the Mammalia based on skeletal traits (distinct from and contra to a cladogram based on DNA). Yesterday we looked at the deep time chronology of mammals. Today we add size categories to the cladogram to indicate Cope’s Rule (size increase over time) and phylogenetic miniaturization (size decrease over time, Fig. 1).

Looking at various mammal taxa size categories:

Figure 2. Subset of the LRT focusing on mammals. Color bars indicate size categories.

Figure 2. Subset of the LRT focusing on mammals. Color bars indicate size categories. The general trend is toward larger taxa with only a few phylogenetic miniaturization reversals.

Some notes:

  1. Mouse-sized taxa are typical at the origin of the Mammalia and the Metatheria (Marsupialia) with a few taxa growing to cat-sized. The few human-sized taxa are wolf-like or kangaroos. The two cow-sized metatherians are giant wombats.
  2. Cat-sized taxa are typical at the origin of the Eutheria (placentals). Larger taxa do not appear until after the large dinosaurs became extinct. Note: during the Mesozoic some large pre-mammals, like Repenomamus, remained.
  3. There are no elephant-sized prototheres or metatheres.
  4. There are no mouse-sized taxa more derived than Maelestes and close kin.
  5. Phylogenetic miniaturization attends the origin of mammals, the origin of the Hadrocodium clade, and after the glyptodonts. Little to no evidence of miniaturization appears at the origin of metatherians and eutherians. Slight evidence of miniaturization also appears at Ocepeia (pre mysticetes), Cainotherium (pre-artiodactyls) and Ectocion (pre-hyrax/elephant/siren).

Much earlier we looked at birth types (helpless vs. able) in a previous cladogram of the Mammalia that is as up-to-date as this one, but the point is made. We also briefly looked at the flexible spinal column of basal mammals vs. the less flexible spine of derived mammals.

Largest ‘flying reptile’ from the Crato formation? Maybe not.

Cheng et al. 2018
report on a partial wing finger (MPSC R 1221, Fig. 1) that they say represents, “The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil.”

But is it? 

Figure 1. The as yet undescribed SMNS PAL 1136 specimen is much larger than comparable bones in the new specimen, MPSC R 1221.

Figure 1. The as yet undescribed SMNS PAL 1136 specimen is much larger than comparable bones in the new specimen, MPSC R 1221. If the scale bars are correct, the SMNS specimen is much larger.

No…
if the scale bars are correct. The larger, as yet undescribed, and very impressive SMNS PAL 1136 specimen (Fig. 1) is not mentioned in the text. I do not know if the SMNS specimen is from the Crato or Roualdo formation (I have not gone back to look up that datum). In any case, the authors overlooked this specimen, because it is not mentioned in the text or charts that list a few dozen other large pterosaurs. It should have been included. Of course, then the headline would have read, “…second largest…” and no one wants that.

So was this oversight intentional?
We’ll never know. The SMNS specimen has been in the literature for 24 years (Frey and Martill 1994).

Addendum several days later
The Crato Formation was not erected until 13 years after the 1994 paper by Martill, Bechly and Loveridge. Therefore all layers were considered Santana Formation in 1994. So the SMNS specimen from the Santana formation might have come from the upper or lower layers. It should have been included in the 2018 survey.

The authors conclude
“Based on the fusion of the extensor tendon process and the first wing phalanx and bone histology, MPSC R 1221 presents a subadult individual of a late ontogeny stage (OS5) at time of death, whichmeans that the final maximized wingspan might have been larger. This is corroborated by the osteohistological sections since this individual did not present an external fundamental system.” Look how eager the authors are to hang on to that superlative, ‘largest’, even though we know of at least one that is so much larger.

The authors do not realize
or continue to deny data, that pterosaurs do not follow archosaur fusion patterns during ontogeny—because pterosaurs are not archosaurs, and their fusion patterns follow phylogenetic patterns.

I never heard the term,
“external fundamental system” before. So, I looked it up: “A closely spaced series of lines of arrested growth that is called the External Fundamental System (EFS) indicates that adult size has been reached.” Now we all know!

I hope this blog post
will one day turn out dozens of young paleontologists who will read every paper they see with a seasoned and skeptical eye. If so, a few of you may someday become editors of academic journals or manuscript referees. When that happens, don’t let mistakes like this slip out. Having a website, like ReptileEvolution.com, that is full of data and illustrations, makes it easy to fact-check superlative claims, like this one, with just a few clicks.

On that note:
here (Fig. 2) is a published illustration of a pterosaur wrist from Duque and Barret 2018 with labels that were a little mixed up with regard for the ulna and radius. The referees should have caught this.

Figure 1. From figure 9 from Duque and Barreto 2018 with corrections noted and digit 5 colorized

Figure 2. From figure from Duque and Barreto 2018 with corrections noted and digit 5 colorized. This mistake should have been caught by the authors and referees, not me.

References
Cheng X, Bantim RAM, Sayão JM, Kellner AWA, Wang X and Saraiva AAF 2018. The largest flying reptile from the Crato Formation, Lower Cretaceous, Brazil. Historical Biology. https://doi.org/10.1080/08912963.2018.1491567
Duque RRC and Barret AMF 2018. New exceptionally well-preserved Pterosauria from the lower Cretaceous Araripe Basin, Northeast Brazil. Cretaceous Research 10.1016/j.cretres.2018.05.004
Frey E and Martill DM 1994. A new Pterosaur from the Crato Formation (Lower Cretaceous, Aptian) of Brazil. Neues Jahrbuch für Geologie und Paläontologie, Abhandlungen 194: 379–412.

Largest birds and pterosaurs to scale (finally!)

Question: Could the largest azhdarchids fly?
Tradition says: Yes! Most pterosaur workers say: Yes! Flying azhdarchid models say: Yes!

Heresy:
We looked at that question earlier and came to another conclusion based on comparable vestigial wingtip phalanges in flightless pterosaurs. Today there’s more to consider.

Let’s take another look at that same problem,
this time comparing the largest flying bird to the largest flying pterosaurs, and the largest non-flying bird to a giant pterosaur (Fig. 1). Since the largest flying birds and pterosaurs had the longest wing/neck and wing/torso ratios, the reduction of wing span/neck length points toward flightlessness—if analogous.

As reported yesterday,
lacking the ability to fly removes the constraints for multiple increases in size. We know of no pterosaurs that had vestigial wings, only vestigial distal wing phalanges. Three of the four flightless pterosaurs we looked at earlier were pterodactyloid-grade quadrupeds, so their free fingers had to contact the substrate. Moreover, all flightless pterosaurs could still flap vigorously, whether to ward off threats by display and/or increase thrust while fleeing.

Figure 1. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale.

Figure 1. Click to enlarge. The largest flying and non-flying birds and pterosaurs to scale. Are large soaring birds analogs to large flying pterosaurs. If so, then are large non-flying birds analogs to large non-flying pterosaurs. Does giving up flight enable giantism in birds and pterosaurs?

While recognizing obvious differences
between the largest pterosaurs and birds, which are more alike?

On the one hand
we have pterosaurs and birds with shorter necks, shorter legs and longer wings.

On the other hand
we have a pterosaur and a bird with a longer neck, longer legs and a relatively shorter wing (compared to those of volant pterosaurs). Is it really as simple as that?

Or did I cherry-pick taxa?

Figure 2. Azhdarchids are stork-like waders, so Ciconia, the stork, is a good analog. It is notably smaller than the smallest known Quetzalcoatlus.

Figure 2. Azhdarchids are stork-like waders, so Ciconia, the stork, is a good analog. It is notably smaller than the smallest known Quetzalcoatlus, about the size of flying azhdarchids.

Azhdarchids are often compared to storks.
And they do have similar proportions (Fig. 2). But all storks fly and some of the largest (e.g. Ciconia) are only half as tall as the smallest Quetzalcoatlus sp. We know of no giant storks. Even so, at half as tall, the legs of Ciconia were equal in length to the larger Q. sp, the torso was similar in size, and the neck and skull were only half as long. All this would appear to make azhdarchids top heavy relative to the volant stork (Fig. 3), despite a longer wing span, even with reduced distal elements.

Figure 3. Q. northropi and Q. sp. compared to Ciconia, the stork, and Pelagornis, the extinct gannet, to scale. That long neck and large skull of Quetzalcoatlus would appear to make it top heavy relative to the volant stork, despite the longer wingspan. Pteranodon and other flying pterosaurs do not have such a large skull at the end of such a long neck (Fig. 1). The longer wings of pelagornis show what is typical for a giant volant tetrapod, and Q. sp. comes up short in comparison.

Figure 3. Q. northropi and Q. sp. compared to Ciconia, the stork, and Pelagornis, the extinct albatross/gannet, to scale. That long neck and large skull of Quetzalcoatlus would appear to make it top heavy relative to the volant stork and gannet, despite the longer wingspan compared to the stork. Pteranodon and other flying pterosaurs do not have such a large skull at the end of such a long neck (Fig. 1). The longer wings of Pelagornis show what is typical for a giant volant wide-ranging tetrapod, and Q. sp. comes up short in comparison.

What about those wings?
Compared to the stork, Q sp. had longer wings. Compared to albatrosses and pterosaurs, Q. sp. had shorter wings. In any case, that long neck is strikingly different in azhdarchids. Such a long lever arm had to affect the center of balance (Fig 3 red line).

Figure 3. Quetzalcoatlus model ornithopter by Paul Macready getting walked to its take-off point.

Figure 4. Quetzalcoatlus model ornithopter by Paul Macready getting walked to its take-off point. The wing chord extends to the posterior pelvis, which is invalid. The demonstrated wing chord is shown in figure 3.

What about that mechanical flying Q. sp?
Paul Macready built and flew a gliding Q. sp., (Fig. 4) not a Q. northropi. It did not have a long enough neck or large enough skull. As it was, it was well-engineered and all the mechanics in the torso were unlikely duplicated in the Late Cretaceous taxon.

Figure 5. The Macready flying model compared to Q. sp. Perhaps it has always been overlooked that the neck proportions were changed and heavy mechanical motors and batteries filled the torso.

Figure 5. The Macready flying model compared to Q. sp. Perhaps it has always been overlooked that the neck proportions were changed and heavy mechanical motors and batteries filled the torso. The hind limbs are unnaturally tucked in in the model, following Kevin Padian’s invalidated view that pterosaurs were close to dinosaurs.

The question(s) comes down to:
If large soaring birds are analogs to large flying pterosaurs, then are the largest non-flying birds analogs to the largest pterosaurs? Does giving up flight enable and promote gigantism in birds AND pterosaurs?

At present, the evidence says: yes.

However, it’s not that giant pterosaurs were “too big to fly”.
Here’s the working hypothesis: Smaller pterosaurs that stopped flying were then able to grow much bigger, with less constraint for maintaining a center of balance at the shoulders.

Quetzalcoatlus running like a lizard prior to takeoff.

Figure  6. Quetzalcoatlus running like a lizard prior to takeoff. Leaning forward while running fast is what humans do to. Perhaps the neck was held more erect, like an ostrich or giraffe, back in the Late Cretaceous.

Not sure why it took so long
to put large pterosaurs and birds together. This should have been posted years ago.

 

A giant Romanian pterosaur mandible fragment

FIgure 1. LPB R 2347 largest pterosaur mandible compared to Bakonydraco.

FIgure 1. LPB R 2347 largest pterosaur mandible compared to Bakonydraco.

Vremir et al. 2018
describe a pterosaur mandible fragment (Figs. 1, 2), “This specimen represents the largest pterosaur mandible ever found and provides insights into the anatomy of the enigmatic giant pterosaurs.”

Figure 2. LPR pterosaur mandible compared to related taxa, like Eopteranodon, and to the largest known pterosaur, Quetzalcoatlus. Figure 2. LPR pterosaur mandible compared to related taxa, like Eopteranodon, and to the largest known pterosaur, Quetzalcoatlus.

Figure 2. LPR pterosaur mandible compared to related taxa, like Eopteranodon, and to the largest known pterosaur, Quetzalcoatlus to scale.

It’s worthwhile
to place the jaw fragment in context with other pterosaurs. We don’t have a similar jaw fragment for the big Quetzalcoatlus (Fig. 2), which likely stood twice as tall as the giant eopteranodontid owner of the jaw fragment. Bakonydraco is a likely eopteranodontid, larger than Eopteranodon, but much smaller than the jaw fragment owner.

Earlier this jaw fragment was used as the basis for restoring the rest of this pterosaur as a giant azhdarchid nicknamed, ‘Dracula’ (with beaucoup errors, Fig. 2).

Figure 1. Dracula the giant azhdarchid pterosaur museum mount. Hopefully it's not too late to fix the problems here.

Figure 2. Dracula the giant pterosaur model built and based on the jaw fragment in today’s post. That’s a lot of imagination!

References
Vremir M et al. 2018. Partial mandible of a giant pterosaur from the uppermost Cretaceous (Maastrichtian) of the HaÈeg Basin, Romania. Lethaia doi: https://doi.org/10.1111/let.12268 https://onlinelibrary.wiley.com/doi/abs/10.1111/let.12268