Aetogate: Martz's response to Spencer Lucas

Mon Mar 10 14:36:16 GMT 2008


In his recently posted response to our allegations, Spencer Lucas attempted to refute our claim that Spielmann et al. (2006) had committed plagiarism by taking credit for an interpretation of the aetosaur Redondasuchus made previously by Martz (2002). Lucas's refutations do not hold up under scrutiny.

To summarize briefly the relevant literature on Redondasuchus: Hunt and Lucas (1991) named the taxon, with the holotype being an osteoderm that they interpreted as coming from the left side of the body. This interpretation gives the osteoderm a downturned lateral edge two-thirds of the distance from the medial edge. This interpretation was reflected in their diagnosis and discussion and had great import to their interpretation of the taxon. Heckert et al. (1996) gave the same interpretation, always referring to the osteoderm as a left, and diagnosing and discussing it the same way. Heckert and Lucas (2000) also diagnosed Redondasuchus as having a downturned lateral edge, two-thirds the distance from the medial edge.

Martz (2002) corrected this interpretation, noting that the holotype was actually right-sided, and noting that that placed the "arching" or "flexing" closer to the medial edge (only one-third the distance), as is typical of aetosaur osteoderms. Spielmann et al. (2006) made the same interpretation and explicitly stated that the older interpretation in the 1991, 1996, and 2000 papers was wrong. However, Spielmann et al. claimed to have come up with the re-interpretation themselves and did not cite Martz (2002) as having made it first, or at all, even though Martz sent nearly all authors copies of his thesis early in 2003. The 2006 paper managed to cite the Martz thesis extensively on matters they disagreed with.

In his response to our allegations, Lucas makes some fairly stunning claims. He states that "In 2006, Spielmann independently reached the conclusion that the armor plate was from the right side and easily convinced Hunt, Lucas, and Heckert of this." Before Spielmann, however, Hunt, Lucas, and Heckert already all had copies of Martz's thesis, giving this same interpretation since 2003. It is hard to see therefore how Spielmann's observation could be called "independent," or how these authors could claim even partial credit in 2006 for a correction known to them in 2003.

Lucas also tries to make the case that Heckert et al. (1996) actually had made the correct interpretation that the type osteoderm is a right, and that the arching is closer therefore to the medial edge, but that this was vague because of "inconsistencies" in the text. In fact, there are no inconsistencies in the way these authors discuss Redondasuchus: they consistently give the erroneous interpretation as a left osteoderm with the flexing closer to the lateral edge. Heckert et al. (1996) and Heckert and Lucas (2000) give this interpretation clearly in their diagnosis, and it is essential to their discussion of the morphological uniqueness of the taxon. Additionally all the authors involved in the 1991, 1996, and 2000 papers are co-authors in the Spielmann et al. (2006) paper, which flatly states (p. 583) that the interpretation given by Hunt and Lucas (1991) and Heckert et al. (1996) was incorrect:

These studies suggested that, for the mid-dorsal paramedian scutes, the point of flexure was "two-thirds of the lateral distance from the medial to lateral edge of the scute" (Heckert et al., 1996, p. 620). However, we believe that this is incorrect and that the point of flexure instead lies one-third of the lateral distance from the medial to lateral edge of the scute (Fig. 1). [Italics added]

Lucas's response claims that even though the 1996 and 2000 papers always describe the type scute as a left, and depend on this erroneous interpretation for their diagnosis and discussion of the taxon, they actually mean exactly the opposite if one reads carefully. This is not a compelling argument. Lucas's rationales for this bizarre argument make little sense. For example, Lucas argues that as Heckert et al. (1996) identified the anterior bar, they must have known which end was medial and which was lateral. This is false. The erroneous interpretation of the osteoderm as a left correctly places the anterior bar along the anterior edge of the osteoderm. The difference between the erroneous and correct interpretations depends only on whether then center of flexion is closer to the medial or lateral edges, and these papers all explicitly place it closer to the lateral edge.

Lucas states that as Spielmann et al. (2006) cited Martz (2002) extensively, they clearly intended to give him credit. This is not so. As we explained very clearly in our original letter, Spielmann et al. (2006) cited Martz (2002) only on points they disagreed with. They otherwise took sole credit for the corrected interpretation (see above quote), and did not acknowledge Martz at all for having made this interpretation. If anything, their extensive citation of Martz on matters they disagreed with makes their omission on the point even more blatant. This was expained in our original letter to the DCA but ignored in Lucas's response.

Lucas also claims that Spielmann et al's (2006) Figure 1 was based on Heckert et al. (1996), and is not identical to Martz's (2002) Fig. 3.1 as we alleged. Spielmann et al's (2006) figure has two sections, one on the left showing the old, incorrect interpretation, and one on the right showing the corrected interpretation. The old interpretation is taken from Heckert et al. (1996). The modified interpretation on the right is clearly the same one given by Martz's (2002) Fig. 3.1. Contrary to Lucas' s claim, we never said the figure was taken directly from Martz's thesis, only that it showed the same reorientation. The significance of this is that it is impossible for Spielmann et al. (2006) to somehow be unaware that Martz made the same reorientation, given that they extensively cite this section of his thesis, and even cite part of the same figure.

As a final note, Lucas pointed out that we erroneously said that the 2006 paper was not submitted for peer review. Lucas is correct in identifying this as an error. Jerry Harris and Robert Sullivan are indeed acknowledged as reviewers for the paper. However, although both Dr. Harris or Dr. Sullivan have published papers on the Triassic, neither (to the best of my knowledge) work on aetosaurs, so the fact that "neither detected any impropriety in the article" is not surprising