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Journal of Creation 34(3):8–9, December 2020

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Colonial nesting or hurried egg laying by dinosaurs?

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duck-billed-dinosaur-egg
Figure 1. A lambeosaurine, duck-billed dinosaur egg clutch found in north-central Montana, USA, and displayed at the Museum of the Rockies, Montana State University, Bozeman, Montana

Uniformitarian scientists often observe features that are difficult to explain in their paradigm. However, they interpret them by adding secondary hypotheses because of their allegiance to uniformitarianism and evolution. They do this without evidence, adding interpretations that go beyond the data. It can be difficult to spot their creative (and fanciful) solutions, especially when we are not privy to all the data. For instance, a recent report of egg clutches found in the Javkhlant Formation in the eastern Gobi Desert of Mongolia.1

The observations

Millions of dinosaur eggs are found in sedimentary rocks all over the world. They are often found in clutches (figure 1). In the Gobi Desert, Tanaka et al. observed eggs in at least 15 clutches with 3 to 30 eggs in each clutch with no discernible arrangement.1 Half of the area has been eroded, so it is likely there once were twice as many clutches. The egg clutches were found on top of a common paleosurface of sandy, light gray mudstone. Sometimes they were bunched up with the shortest distance apart less than 1.5 m and an average of one clutch per 10 m2. The clutches cover an area of about 286 m2. The eggs had an average diameter of 13 cm with a range of 10–15 cm, and the shells were an average of 1.55 mm thick and very porous. The upper part of many of the eggs has been lost to modern erosion.

The scientists observed that the sediments within the eggs consisted of two distinct layers: (1) a lower, dull orange, sandy mudstone 3–5 cm thick, and (2) an overlying, red very sandy mudstone 1–6 cm thick. Each layer was fining upward, as if laid in a current. Above the red mudstone, the dull orange mudstone continued, both of which were laterally extensive. The upper red mudstone layer contained mud clasts, pebbles, volcanic fragments, and caliche pebbles, also found in the gray mudstone below the eggs. The caliche is interpreted as pedogenic.

The faulty uniformitarian interpretations

The scientists claim that the area is a colonial nesting area of likely therizinosauroid theropod dinosaurs. The egg clutches were said to be nests that were fully covered and incubated by the dinosaurs:

“Although no sedimentological evidence indicative of nest structure was found associated with the Javkhland clutches, statistical methods were used to infer nest type (i.e. covered versus open). Based on a linear discriminant analysis between egg mass and eggshell porosity in extant archosuars (Tanaka et al., 2015), the high porosity of the Javkhland eggs (646 mm porosity for an egg mass of 1204 g: see the Data Repository) indicates they were incubated in fully covered nests.”2

The scientists are weaving a story around the observations that the eggs were laid on a generally flat paleosurface and that they are highly porous. There is no indication the eggs were covered by soil or vegetation or placed in a hole, or that the clutches were nests. The few dinosaur nests that are found indicate that the eggs would be laid in a dug out hollow with sediment piled upon the sides, as observed on ‘Egg Mountain’, Montana, USA. In fact, there are very few nest structures associated with the numerous dinosaur eggs found anywhere in the world.3 Uniformitarian scientists usually infer a nest by the presence of an egg clutch:

“Despite the relative abundance of dinosaur eggs in the fossil record (Carpenter et al., 1994; Carpenter, 1999), trace-fossil evidence of dinosaur nest construction is extremely rare. The existence of a nest is typically inferred by the presence of an egg clutch and usually it is not accompanied by physical evidence of nest architecture.”4

Chiappe et al. probably feel free to admit this because they think they found six more nests in Argentina. However, these candidate nests are likely dinosaur tracks.5 There is little or no evidence for dinosaur nests, and it is simply an ad hoc uniformitarian interpretation based on the fact that most dinosaur eggs are very porous, similar to reptiles.6

Furthermore, little evidence exists that dinosaur eggs were covered with vegetation to keep them warm and moist:

“The suggestion that some dinosaurs may have nested in vegetation or vegetation-mud mounds similar to those of megapode birds or alligators seems to be a popular idea … but how can this be proven when all traces of vegetation have rotted away? Or how can we determine if vegetation was even used at all?”7

Admitting the traces of vegetation are rare, the idea it rotted away is contradicted by a lack of pollen evidence and the continued existence of delicate dinosaur eggs or shell fragments.

Moreover, it is claimed that the sediments were pedogenic, mainly because of the caliche particles, so the clutches were believed to have been incubated in a soil or organic rich substrate.2 However, the caliche particles could have simply been eroded from a carbonate layer, since there were other indications of erosion such as mud clasts, pebbles, and volcanic fragments. The soil and organic-rich substrate is an inference that appears to have little or no evidence.

The scientists also claim that many “had hatched eggs before the site was buried by flooding.”2 This was because randomly orientated openings in the upper half of the egg from the clutches are reminiscent of a hatching window made by a hatchling escaping the egg. Eggshell fragments up to 6 cm in diameter, similar to the opening in the eggs, were found inside some of the eggs, and eggshells scattered around two clutches. But why would a large eggshell fragment be found within the egg if the hatchling pushed the shell outward? Four clutches not only had open tops but also the red marker bed visible inside, indicating that the eggs were open at the time the upper layer was deposited. Nine clutches had at least one egg that is believed to have hatched, similar or greater than the success of crocodiles and some birds. However, no hatchlings were found. The idea of hatching dinosaur eggs is thus an inference. There are other possibilities, besides hatching, such as erosion by currents and scavenging by predators. The authors list several potential predators found in the Javkhlant Formation, such as turtles, lizards, other theropods, and eutherian mammals.1

The inference that the eggs were all laid at the same time is a good deduction because of the two layers of mudstone in the eggs. However, the authors take this too far because of their belief in evolution:

“When considered in an evolutionary context, this study supports the idea of a gradual acquisition of avian reproductive traits through theropod evolution … although widespread among living birds, nest attendance/protection behavior among colonial nesters appears to have first evolved in non-brooding non-avian dinosaur species.”8

The fact that these clutches are concentrated also indicates that these egg clutches were laid at the same time, but they extrapolate by imagining that this was the beginning of brooding, colonial nesting. Interestingly, the remains of the mother dinosaurs are absent, but they still believe that the dinosaurs must have attended and protected the nests for a while. So, the idea of brooding and nest protection is another unfounded uniformitarian, evolutionary inference.

A BEDS alternative origin

The evidence better supports the BEDS (Briefly Exposed Diluvial Sediments) model during the Flood.9 The evidence indicates that the Gobi Desert eggs were laid on flat bedding planes, as are most other dinosaur egg clutches. It also indicates hasty egg laying since there seems to have been no time for nest construction. The area of exposed sediment must have been small, which explains why so many theropods laid their eggs close together. The authors admit that the eggs were buried in a flood. Although they automatically think it is a local flood because of their assumptions, it could easily have been continued flooding after sediments were briefly exposed in the Genesis Flood.

References and notes

  1. Tanaka, K., Kobayashi, Y., Zelenitsky, D.K., Therrien, F., Lee, Y.-N., Barsbold, R., Kubota, K., Lee, H.-J., Chinzorig, T., and Idersaikhan, D., Exceptional preservation of a Late Cretaceous dinosaur nesting site from Mongolia reveals colonial nesting behavior in a non-avian theropod, Geology 47(9):843–846, 2019. Return to text.
  2. Tanaka et al., ref. 1, p. 845. Return to text.
  3. Oard, M.J., Evidence of dinosaur nest construction is extremely rare, J. Creation 19(2):21–22, 2005. Return to text.
  4. Chiappe, L.M. et al., Nest structure for sauropods: sedimentary criteria for recognition of dinosaur nesting traces, Palaios 19:89, 2004. Return to text.
  5. Grellet-Tinner, G., Fiorelli, L.E., and Salvador, R.B., Water vapor conductance of the Lower Cretaceous dinosaurian eggs from Sanagasta, La Rioja, Argentina: paleobiological and paleoecological implications for South American faveoloolithid and megaloolithid eggs, Palaios 27:35–47, 2012. Return to text.
  6. Oard, M.J., The meaning of porous dinosaur eggs laid on flat bedding planes, J. Creation 27(1):3–4, 2013; creation.com/dinosaur-eggs. Return to text.
  7. Carpenter, K., Eggs, Nests, and Baby Dinosaurs: A look at dinosaur reproduction, Indiana University Press, Bloomington, IN, p. 165, 1999. Return to text.
  8. Tanaka et al., ref. 1, p. 846. Return to text.
  9. Oard, M.J., Dinosaur Challenges and Mysteries: How the Genesis Flood makes sense of dinosaur evidence—including tracks, nests, eggs, and scavenged bones, Creation Book Publishers, Powder Springs, GA, 2011. Return to text.