NatGeo article on private ownership of dinosaur fossils

We’ve known OF them,
now we get to meet some of the wealthy individuals who buy fossil dinosaur, mosasaur and pterosaur skeletons for their atria, offices and man-caves. Going direct to the source, one ophthalmologist dug up his own mosasaur which, after cleaning and mounting, now hangs over his living room. “Being in their presence, he says, awakens ‘a very spiritual feeling of connection with the history of life.’” I imagine his wife doesn’t have that same appreciation.

Writer Richard Conniff reports,
“The passion for paleontology among private collectors means that dinosaurs and other fossil giants can turn up in homes and businesses almost anywhere.”

Referencing the 1997 auction of a T. rex
that ended up in Chicago’s famed Field Museum, Conniff writes, “It also left many museum paleontologists fearful that they’d be priced out of a domain they’d long considered their own.” 

A domain they’d long considered their own…
hmmm.

Conniff lets us in on a little secret, 
“the gold rush never quite materialized. There’s a glut of Tyrannosaurus specimens on the market now, and other prize specimens sell only after years of price-cutting.”

Wonder if this article will inspire the market
for dino bones or help depress it? In any case, casts are always available. I have and have had several. They are wonderful, realistic and no one cares if you have one or not.

Back in the day
I owned several fossils that I ‘loaned’ (that’s how they do it nowadays) several years ago to the struggling paleo department at Washington University here in St. Louis. Here’s one, a fairly large Triassic theropod track with nice details. Visitors can see it any time they want, and I never have to dust it. It’s better this way.

Figure 1. A Triassic dinosaur track from the collection of David Peters on loan at Washington University, St. Louis.

Figure 1. A Triassic dinosaur track from the collection of David Peters on permanent loan at Washington University, St. Louis.

Funny thing about discoveries,
once you’ve made them and reported them, you’re off to the next one. So, perhaps it’s no wonder the fossil owners look so nonchalant in all the Nat Geo pix.


References
NatGeo article online here

What is Dyoplax?

Updated August 9, 2019
with a recently downloaded loaded photo of the skull (Fig. 3) from Maisch, Matzke and Rathgeber  2013. The DGS version sutures are distinct from those of Maisch et al.. The LRT nesting did not change.

Figure 1. Dyoplax arenaceus Fraas 1867 is a mold fossil recently considered to be a sphenosuchian crocodylomorph. Here it nests as a basal metriorhynchid (sea crocodile) in the Late Triassic.

Figure 1. Dyoplax arenaceus Fraas 1867 is a mold fossil recently considered to be a sphenosuchian crocodylomorph. Here it nests as a basal metriorhynchid (sea crocodile) in the Late Triassic.

Dyoplax arenaceus (Fraas 1867, Lucas, Wild and Hunt 1998) is a unique Late Triassic crocodylomorph, one of the three original crocodylomorphs in the 19th century along with two aetosaurs.

No bones are present.
Like Cosesaurus it is a natural cast mold. Fraas thought it had the head of a lizard, but the armor of a gavial. Lucas et al. nested it as the oldest sphenosuchian crocodylomorph. Maish et al. nested it with Erpetosuchus.

Here
Dyoplax nests as a basal metriorhynchid, those Jurassic sea crocodiles with flippers for fore limbs and a curved fish-like tail (Fig. 2), which was probably too early to be present. Unfortunately the tail tip and limb tips are missing from the fossil (Fig. 1)

The fossil appears to have no arch of bones separating the upper and lateral temporal fenestrae, but the intervening squamosal appears to be flipped and displaced near the neck ribs. (Black arrow in fig. 1)

Figure 2. Several Jurassic sea crocs, apparently derived from Late Triassic Dyoplax.

Figure 2. Several Jurassic sea crocs, apparently derived from Late Triassic Dyoplax.

Figure 3. Added 08/09/19 from Maisch et al. 2013. DGS sutures do not match sutures found by Maisch et al. (drawing) Hypothetical missing parts based on phylogenetic bracketing ghosted on in color

Figure 3. Added 08/09/19 from Maisch et al. 2013. DGS sutures do not match sutures found by Maisch et al. (drawing) Hypothetical missing parts based on phylogenetic bracketing ghosted on in color

References
Fraas O 1867. Dyoplax arenaceus, ein neuer Stuttgarter Keuper-Saurier. Jh. Verein vaterländ. Naturk. Württemberg 23:108-112; Stuttgart.
Lucas SG, Wild R, Hunt AP 1998. Dyoplax O. Fraas, a Triassic sphenosuchian from Germany. Stuttgarter Beiträge zur Naturkunde, B. 263: 1–13.
Maisch MW,  Matzke AT and Rathgeber T 2013. Re-evaluation of the enigmatic archosaur Dyoplax arenaceus O. Fraas, 1867 from the Schilfsandstein (Stuttgart Formation, lower Carnian, Upper Triassic) of Stuttgart, Germany. Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen. 267 (3): 353–362.

 

Hypsibema missouriensis – a Late Cretaceous Appalachia duckbill dinosaur

Figure 1. Model of Hypsibema missouriensis, a hadrosaurid dinosaur

Figure 1. Model of Hypsibema missouriensis, a hadrosaurid dinosaur

Hypsibema missouriensis
(Cope 1869; Gilbert and Stewart 1945; Gilbert 1945; Baird and Horner 1979; Darrough et al. 2005; Parris 2006; Campanian, 84-71 mya, Late Cretaceous) is a fairly large hadrosaurid dinosaur discovered in 1942, at what later became known as the Chronister Dinosaur Site near Glen Allen, Missouri. At present this literal pinprick in the map of Missouri is the only site that preserves dinosaur bones.

Figure 2. Where the Hypsibema maxilla chunk came from on the skull of Saurolophus.

Figure 2. Where the Hypsibema maxilla chunk (Figure 3) came from modeled on the skull of Saurolophus.

Small pieces of broken bone and associated caudals and toes
were first discovered when digging a cistern. They had been found about 8 feet (2.4 m) deep imbedded in a black plastic clay. The area is in paleokarst located along downdropped fault grabens over Ordovician carbonates.

Gilmore and Stewart 1945 described a series of Chronister caudal centra (now at the Smithsonian) as sauropod-like, reporting, “The more elongate centra of the Chronister specimen, with the possible exception of Hypsibema crassicauda Cope, and the presence of chevron facets only on the posterior end appear sufficient to show that these vertebral centra do not pertain to a member of the Hadrosauridae.”

First named Neosaurus missouriensis,
the caudals were renamed Parrosaurus missouriensis by Gilmore and Stewart 1945 because “Neosaurus” was preoccupied. The specimen was allied to Hypsibema by Baird and Horner 1979.

Figure 3. Back portion of a Hypsibema maxilla showing tooth root grooves and cheek indention close to jugal.

Figure 3. Back portion of a Hypsibema maxilla showing tooth root grooves and cheek indention close to jugal.

Back in the 1980s
I enjoyed going to the Chronister site with other members of the local fossil club, the Eastern Missouri Society for Paleontoogy. I was lucky enough to find both a maxilla fragment (Fig. 3) and a dromaeosaurid tooth. I remember the horse flies were pesky and  one morning, before the other members got there, I was met by a man with a shot gun who relaxed when I identified myself. A friend found a series of hadrosaur toe bones, each about as big as a man’s hand (sans fingers). The bone was so well preserved you could blow air through the porous surfaces.

References
Baird D and Horner JR 1979. Cretaceous dinosaurs of North Carolina. Brimleyana 2: 1-28.
Cope  ED 1869.
Remarks on Eschrichtius polyporusHypsibema crassicaudaHadrosaurus tripos, and Polydectes biturgidus“. Proceedings of the Academy of Natural Sciences of Philadelphia 21:191-192.
Darrough G; Fix M; Parris D and Granstaff B 2005.
 Journal of Vertebrate Paleontology 25 (3): 49A–50A.
Gilmore CW and Stewart DR 1945. A New Sauropod Dinosaur from the Upper Cretaceous of Missouri. Journal of Paleontology (Society for Sedimentary Geology 19(1): 23–29.
Gilmore CW 1945. Parrosaurus, N. Name, Replacing Neosaurus Gilmore, 1945. Journal of Paleontology (Society for Sedimentary Geology 19 (5): 540.
Parris D. 2006. New Information on the Cretaceous of Missouri. online

wiki/Hypsibema_missouriensis
bolinger county museum of natural history
More info and links

Variation in Mesenosaurus and Mycterosaurus

Updated February 23, 2015 with a new image of Mycterosaurus.

Mesenosaurus romeri (Efremov 1938, Reisz and Berman 2001) Late Carboniferous to Early Permian ~300 to ~260 mya was originally considered a varanopseid, like Varanops, but it lies outside the varanopsids and outside the synapsids when tested against a larger list of taxa. Here Mesenosaurus was derived from a sister to Archaeovenator and phylogenetically preceded Milleropsis within the Protodiapsida and Eudibamus and Petrolacosaurus within the Diapsida (sans Lepidosauriformes, which nest elsewhere).

The clade of Heleosaurus + Mycterosaurus is a sister to Mesenosaurus (Fig. 1).

Figure 1. Mesenosaurus skulls compared to sisters Heleosaurus and Mycterosaurus. Note the greater angularity of the skull shapes along with the wider posterior skulls in derived taxa (toward the bottom). The SGU specimen needs better data on the squamosal, which is illustrated as missing its ventral/lateral portion here.

Figure 1. Mesenosaurus skulls compared to sisters Heleosaurus and Mycterosaurus. Note the greater angularity of the skull shapes along with the wider posterior skulls in derived taxa (toward the bottom). The SGU specimen needs better data on the squamosal, which is illustrated as missing its ventral/lateral portion here.

The Mycterosaurus question
The Mycterosaurus in figure 1 was illustrated by Williston in 1915. Bones attributed to Mycterosaurus by Reisz et al. 1996 are shown in figure 2. The tooth shapes are not the same. The depth of the maxilla is not the same. Yet the tooth shapes in the Williston image are not the same as those in Heleosaurus and Mesenosaurus. The Reisz et al. images are more similar.

Figure 2. Mycterosaurus bones from a fissure fill formation. Typically such bones are individually preserved, so their association with each other and with a certain genus and species is due to the expert eye of a paleontologist. I note differences in the shapes of Mycterosaurus here compared to the Williston specimen/reconstruction in figure 1. So, the data is confusing.

Figure 2. Mycterosaurus bones from a fissure fill formation. Typically such bones are individually preserved, so their association with each other and with a certain genus and species is due to the expert eye of a paleontologist. I note differences in the shapes of Mycterosaurus here compared to the Williston specimen/reconstruction in figure 1. So, the data is confusing.

Sometimes one trusts an illustration…
especially if that’s the only available data. Other times, especially if the illustration is old, the trust is reduced. Howecer, the holotype is the benchmark. Fissure fill specimens, disarticulated as they are, and recent figures are typically more accurate. But how do they relate to the holotype?

If anyone has better data on the holotype of Mycterosaurus,
like a photograph of, please send it and the accuracy of the large reptile tree will be enhanced.

References
Efremov JA 1938. Some new Permian reptiles of the USSR. Academy of Sciences URSS, C. R., 19: 121-126.
Reisz RR and Berman DS 2001. The skull of Mesenosaurus romeri, a small varanopseid (Synapsida: Eupelycosauria) from the Upper Permian of the Mezen River basin, northern Russia. Annals of the Carnegie Museum 70: 113-132. online pdf
Reisz RR, Wilson H and Scott D 1996. Varanopseid synapsid skeletal elements form Richards Spur, a Lower Permian fissure fill near Ft. Sill, Oklahoma. Oklahoma Geology Notes 56 (3):160-170.

wiki/Mesenosaurus

Variations on a Cutleria Restoration

Crushed fossils missing some of the middle/connecting bones give paleontologists several options for restoration. Case in point: Cutleria (Figs. 1, 2) a very basal therapsid. We looked at this specimen/taxon earlier here and here.

Figure 1. Cutleria restoration version 1, straight maxilla.

Figure 1. Cutleria restoration version 1, straight maxilla. Click to enlarge.

The first restoration aligns the ventral maxilla in a straight line. Note the very deep reflected lamina on the angular, sharply angled from the dentary.

Figure 2. Cutleria restoration version 2, convex maxilla.

Figure 2. Cutleria restoration version 2, convex maxilla. Click to enlarge.

The second restoration (Fig. 2) is the more conservative (more like the in situ fossil) producing a deeper, ventrally convex maxilla. Note the reflected lamina of the angular is not so deep here. In both cases the mandible needs to mate to the maxilla, so it changes in each case, enabled by the mid-length break.

Which one is more correct?

Factors to consider:

  1. Ancestral taxa (like Haptodus and Ophiacodon) have a shallow reflected lamina.
  2. Descendant taxa (like Biarmosuchus) have a deeper reflected lamina; but then
  3. Other descendant taxa (like Stenocybus) have a shallow reflected lamina.
  4. Descendant taxa (like Haptodus and Ophiacodon) have a convex maxilla.
  5. Descendant taxa (like Biarmosuchus have a less convex to straight maxilla.
  6. Other descendant taxa (like Stenocybus, dromasaurs, dicynodonts and other therapsids) have a convex maxilla.
  7. Version 2 requires less bone movement.
  8. Version 1 requires less ‘putty’ to fill in holes left by missing bones. The puzzle pieces fit tighter.
  9. The strong posterior lean of the lateral temporal fenestra is not present in either ancestral or descendant taxa and it probably reflects the angle of the mandible adductor.

Your opinion or insights would be appreciated. 

 

A near perfect, pristine Pterodactylus skull

Figure 1. Pterodactylus skull, privates collection,  from "Weber 2013 Paleoeocology of pterosaurs 3 : Solnhofen". French Paleontological survey "Fossiles".

Figure 1. Pterodactylus skull, privates collection, from “Weber 2013 Paleoeocology of pterosaurs 3 : Solnhofen”. French Paleontological survey “Fossiles”. Bones colorized below, both images flipped left to right. Black dots indicated fenestra. Anterior slit is secondary naris, which originated in Scaphognathus. Note the jugal and nasal extend to it. The premaxilla appears to have only three teeth, but look more closely and the nubbin-like medial tooth is still visible. Here you can also see the medial sheet bone in the anterior antorbital fenestra. It is not a fossa.

Luckily this specimen was buried before being crushed, so the cracking one sees in other fossils are absent here. Not sure what the rest of the specimen looks like. This privately owned and expertly prepared Pterodactylus specimen can be considered “pristine” and it offers uncluttered insights into the small pterosaur skull, including the tiny nares, the medial sheet dividing the anterior antorbital fenestra, the laminated jugal and nasal, and the nubbin of a medial pmx tooth. Thanks to Frédéric Weber for providing the image.

Figure 2. Closeup of the rostrum of this private Pterodactylus specimen with bone laminations identified.

Figure 2. Closeup of the rostrum of this private Pterodactylus specimen with bone laminations identified. Without other specimens, like Scaphognathus, that show the secondary naris developing, there would be more reason to dismiss these minor shapes as taphonomic cracks and such.

We don’t look at such imagery in a vacuum. Rather we note that this sort of morphology shows up first in Scaphognathus (Fig. 3) and is retained, more or less, in its many pterosaurian descendants.

Figure 3. New reconstruction of Scaphognathus with the new foot and wing phalanges added.

Figure 3. New reconstruction of Scaphognathus with the new foot and wing phalanges added.

Reference:
Image from “Frédéric Weber 2013 Paleoeocology of pterosaurs 3 : Solnhofen”. French Paleontological survey “Fossiles.”

Another Fish-Pterosaur Drama in the Jurassic

Earlier we were delighted to see a Jurassic drama frozen in time as an Aspidorhynchus fish and Rhamphorhynchus pterosaur were fossilized together in an extremely rare fossil. (Fig. 1, Frey and Tischlinger 2012).

Rhamphorhynchus entangled with Aspidorhynchus

Figure 1. Rhamphorhynchus entangled with Aspidorhynchus (WDC CSG 255). Both complete and articulated. Inside the belly of Rhamphorhynchus are several smaller fish. Inside its throat is another. Image from Frey and Tischlinger (2012).

Now there’s a pair of them!
When I first saw the second Aspidorus-Rhamphorhynchus fossil (Fig. 2), at first I thought it was identical. But it is only the same situation and (nearly) the same players. Not the same pose. Well, the fish is looking over its left shoulder again. But now it looks like they’re dancing — slow dancing.

Figure 2. New Rhamphorhynchus-Aspidorhynchus death struggle from the Beat Imhof collection.

Figure 2. New Rhamphorhynchus-Aspidorhynchus death struggle from the Fascination Minerals collection.

Revelation of the fish/pterosaur drama began in 2007 with the exposure of the pterosaur skull. Only a stain marked the position of the fish as shown in this 3 frame movie (click to animate, Fig. 3).

Figure 3. Click to animate. Exposing the Jurassic drama of the fish and pterosaur is shown here, from raw fossil to carefully prepared display. From the Beat Imhof collection.

Figure 3. Click to animate. Exposing the Jurassic drama of the fish and pterosaur is shown here, from raw fossil to carefully prepared display. From the Fascination Minerals collection.

A reconstruction of the Rhamphorhynchus is shown here (Fig. 4). I’ll add it to a phylogenetic analysis later, but it seems to have a distinct rostral profile, long torso, short arms and robust wings. It’s also on the large side.

Figure 4. Rhamphorhynchus from the Imhof collection.

Figure 4. Rhamphorhynchus from the Fascination Minerals collection.

Here (Fig. 5) are the two Rhamphorhynchus specimens featured today along with their 60cm dance partner, all to the same scale.

Fig. 5. Rhamphorhynchus specimens that have been bitten and fossilized with Aspidorhynchus, a Solnhofen fish of 60cm length.

Fig. 5. Two Rhamphorhynchus specimens that have been bitten and fossilized with Aspidorhynchus, a Solnhofen fish of 60cm length. The skull of the Fascination Minerals specimen (at left) is at the bend of the fish. The other is the Thermopolis specimen WDC CGS 255.

It’s rare to find two species interacting in the fossil record.
So it makes news when it happens. The above may be breaking news because the supplier of the photograph, Beat Imhof, tells me it has not been published.

Figure 1. I know, it's not exactly under our charter, but here one amphibian is choking on another smaller one. Sclerocephalus is the genus.

Figure 6. I know, it’s not exactly under our charter, but here one amphibian is choking on another smaller one. Sclerocephalus is the genus.

Not quite along similar lines, earlier we looked at a cynodont and amphibian sharing the same burrow, and one amphibian eaten by the other (Fig. 6).

References
Frey E and Tischlinger H (2012). The Late Jurassic Pterosaur Rhamphorhynchus, a Frequent Victim of the Ganoid Fish Aspidorhynchus? PLoS ONE 7(3): e31945. doi:10.1371/journal.pone.0031945, available online

The Amphibian within an Amphibian

Everyone has heard of the famous, “Fish within a Fish.” Here (Fig. 1), not quite within, perhaps, but apparently choking on its prey is an amphibian, Sclerocephalus, within (at least partially) another, larger amphibian. News for this fossil up for auction was posted in late September. More here.

Figure 1. I know, it's not exactly under our charter, but here one amphibian is choking on another smaller one. Sclerocephalus is the genus.

Figure 1. I know, it’s not exactly under our charter, but here one amphibian is choking on another smaller one. Sclerocephalus is the genus.

It’s a dog-eat-dog world out there. 
The fossil dates to the Permian period, around 259m-251m years ago. The predator has been identified as a juvenile Sclerocephalus haeuseri – a carnivorous amphibian approximately 28 inches in length. The smaller fossilized amphibian is tentatively identified as another species, Cherlyderpeton latirostris, but it may be a younger version of the animal that ate it.

More here. News as late as November did not indicate the date of the auction or highest bid of the fossil.

 

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

Why you should always keep your dorm room locked.

The rarest of rare fossils finds: Two more-than-friends having a sleepover. Credit to Fernandez et al. 2013.

Figure 1. The rarest of rare fossils finds: Two more-than-friends having a sleepover. Credit to Fernandez et al. 2013. The title of the paper tells it all. A cynodont sleeping with an injured amphibian, in other words a pre-Piggie sleeping with a pre-Kermit. 

References
Fernandez V, Abdala F, Carlson KJ, Cook DC, Rubidge BS, Yates A and Tafforeau P 2013. Synchrotron Reveals Early Triassic Odd Couple: Injured Amphibian and Aestivating Therapsid Share Burrow. PLoS ONE 8(6): e64978. doi:10.1371/journal.pone.0064978.