The Cervantes egg: an early Malagasy tourist to Australia

J. A. Long l, P. Vickers-Rich 2, K. Hirsch J

, E. Bray~ and C. Tuniz'

[Department of Earth and Planetary Sciences, Western AustralIan Museum,Francis Street, Perth, Western AustralIa 6000, Australia

2 Earth Sciences Department, Monash University, Clayton, Victoria 3168, Australia, Universi ty of Colorado, Boulder, Colorado, USA. (deceased)

'Museum Geology section, University of Colorado, Boulder, Colorado, USA.'0 AustralIan Nuclear Science and Technology Organisation, Lucas Heights,

Sydney, New South Wales 2234, AustralIa

Abstract - A large fossil bird's egg discovered near Cervantes in WesternAustralia is identified as belonging to Acpyomis 11117:\II1I1IS by its size andeggshell structure. It is the second such egg found in Western AustralianHolocene beach dune deposits. Radiocarbon dating of the specimen gives anage of about 2000 years. By comparison with other known rafting events, wesuggest th"t this egg and the Scott River Acpyonlls egg both drifted .1cross onOCe.1nlC currents from M.1dagascar and were not brought to Austr.1II'l byhuman intervention.

INTRODUCTION

A large fossil bird's egg (Figure 1) wasdiscovered by three primary school students about7 km north of the town of Cervantes, in WesternAustralia, in late 1992. It represents the secondsuch discovery of a very large fossil bird egg fromthe dune deposits of southern Western Australia,the first being found by Mr Vic Roberts, then tenyears old, near the mouth of the Scott River, nearAugusta in 1930. Well-known naturalist HarryButler saw this egg in a farmhouse in Nannup in1962 and informed the Western AustralianMuseum, which now has the egg (Figure 2) on apermanent loan from Roberts.

The Cervantes egg was found exposed in sanddunes about 300 m inland from the coast. Mory(1994) referred to this egg as being found inHolocene dunes overlying lagoonal deposits,suggesting that the sediments containing the eggwere probably less that 3000 years in age.Radiocarbon dating of the Cervantes egg as about2000 years (see below) fits in well with thissuggested geomorphological age of the dunedeposits.

The Cervantes find was announced to the publicthrough an article in The 5111ldatl Times newspaperon the 21st March 1993 and subsequently receivedan enormous amount of media coverage locally,nationally and even internationally. Despite initialdisputes over the ownership and attempts by thefinders to auction or sell the egg, the WesternAustralian Government eventually made a rulingthat under the r.ands Act the specimen, whichwas found on Crown Reserve Land, actually

belonged to the Crown. An ex gratia payment of$25,000 was later made to the families involved asa goodwill payment. The legal wranglesurrounding the egg's ownership was thusimportant in precipitating the first draftlegislation pertaining to fossils and theirownership for the State of Western Australia.

The Cervantes egg is now a registered specimenin the Western Australian Museumpalaeontological collections, as WAM 93.9.l.Preliminary observations on the egg were firstpublished by Long (1993).

IDENTIFICATION OF THE CERVANTES ANDSCOTT RIVER EGGS

The Cervantes egg measures 31.7 cm in length,being significantly larger than the Scott River eggat 27.6 cm long. Both the Cervantes and Scott Rivereggs appear to belong to the extinct flightless birdAep1lornis 1I117ximllS, which lived in Madagascaruntil as little as 400 years ago (Figure 3). This birdreached gigantic sizes of up to 2.5 m tall and wouldhave weighed more than half a tonne.

The Cervantes eggshell is quite thick, rangingfrom 3.05 to 3.45 mm where it could be measured,and this compares well to the measurements of theMadagascar Elephant Bird, Acpl/ornis. The shellstructure is best viewed in radial thin sections(Figure 4) and is of an ornithoid-ratite morphotype(Hirsch and Packard 1987). There are twopronounced shell layers, the well-structuredmammillary layer and the continuous spongy layerwith an abrupt change of the structure between

40

Figure 1 The Cervantes egg compared with that of achicken egg (photo courtesy of 1.A. Bell).

them. In the case of Aepyomis, a third outer layer ispresent.

The external layer is relatively thick, more sothan that found in the only other omithoid ratite,the Ostrich (Struthio). The continuous inner layer issimilar to that in both the Ostrich and the Emu(Dromaills). This layer has pronounced, horizontalgrowth lines and otherwise looks structureless incomparison to the mammillary layer.

The mammillary layer is almost one third of theeggshell thickness. It has a radial, wedge-likearrangement of the tubular crystalline material,and on the base of the large mammillae aparticularly fine ultrastructure is visible.

The pore canal observed in the Cervanteseggshell is single and non-branching. Aepyomis hassingle or branched pore canals. The pore patternon the surface of the eggshell (Figure 5), openinginto long, narrow slits is very reminiscent ofAepyornis, and not of other ratites. Just as inAepyomis, the pores of the Cervantes egg openedeither singly or multiply in the long pore slits. TheCervantes egg is in the size range and of similarshape to known Aepyomis eggs.

The Scott River egg has a similar eggshell textureto that of the Cervantes egg, but has been sand

I.A. Long, P. Vickers-Rich, K. Hirsch, E. Bray, C. Tuniz

blasted along one side, creating a smooth, polished,but slightly pitted surface.

A comparison to the eggs of large birds knownfrom Australia, the dromornithids, reveals distinctdifferences, namely in the structure of the surfaceareas in which pore canals open. In Genyornis,where this can be well observed, these pore slitsare markedly curved. In the Cervantes egg the slitsare straight. The surface of the Cervantes egg issmooth as in Genyomis, where shell thickness ismuch less (with an average of material wemeasured being about 1.15 mm) and different fromeggs of the largest dromornithid known with athickness of 4.07 mm, which had a crenulated,rough surface (Williams and Rich 1992, 1996).

DATING OF THE CERVANTES EGG

The loose material found inside the egg wasselected for dating on the basis that this samplewas best protected from contamination. Thematerial was extracted using a dentist drill in theclean laboratory at ANSTO.

Organic samples to be analysed by AcceleratorMass Spectrometry (AMS) needed to be purifiedand transformed into graphite target for the ionsource. First CO

2was obtained from two samples,

one of 40 mg and one of 80 mg by hydrolysis inhydrochloric acid under vacuum. The resulting gaswas graphitised onto an iron catalyst using zinc forthe initial reduction to carbon monoxide. Thegraphite/iron mixtures were finally pressed intocathodes and loaded into the iron source on theANTARES AMS spectrometer (Tuniz et al. inpress).

The procedure for the analysis of the l4C/BCisotopic ration is here briefly described. Negativecarbon ions are produced in the sputter ion sourceand, after low-energy mass analysis, they areinjected into the tandem accelerator. High precisionAMS measurements are carried out by rapidsequential injection of the isotopes BC and He.negative ions are attracted to the positive voltageat the terminal and thereby accelerated to energiesof 5.2 MeV at which point they pass through acarbon foil and are stripped of some of theirelectrons. Multi-charged positive ions are thenfurther accelerated by the same positive voltage onthe terminal. The isotopic ration of HC/BC isderived from the 1

4C counting rate in the detectorand the beam current of the stable isotope. Figure 6shows the plot of data upon which the date isbased.

The conventional radiocarbon age for theCervantes egg is 1928 +/-73 yr BP, whichcorresponds to a calibrated age range of 12-187 yrAD (correction for natural isotopic fractionationwa performed by assuming 013 =-14 per mil(Berger 1975)). Conventional radiocarbon ages as

The Cervantes egg

Figure 2 The Scott River egg, found in 1930 near Augusta (photo: Douglas Elford, Western Australian Museum).

41

reported in years BP (before present, wherepresent is 1950 AD) and are calculated using the"Libby" half-life of 5568 years and the assumptionthat the production of 1

4C has been constant. Thedifferences between conventional radiocarbonages and calibrated ages has been determinedwith high precision for most of the Holocene byradiocarbon measurements on tree ring samples,which are independently dated by dendro­chronology. Part of this difference derives fromthe use of conventional half-life, which is knownto be 3% too small. The remaining differencederives from secular variations of 14C productionrate in the atmosphere for geo- and helio-magneticeffects and global variations in the parameters ofthe carbon cycle.

Shell fragments (>10 g) from Aepyornis eggs

found in the sand dunes of Madagascar, have beendated previously using conventional radiocarbonmethods, yielding ages which span the period 850to 7500 yr BP (Berger 1975; Long et al. 1983).

SUPPORT FOR THE DRIFTING EGGHYPOTHESIS

The discovery of the Scott River egg caused quitea stir. Doubt was immediately cast on itsauthenticity. After all, how could a large egg floatacross the Indian Ocean and be washed up on abeach intact? Despite this incredible scenario, theidentification of the egg as an Aepyornis, based onits surface texture, microstructure and overall size,appears most likely. Williams and Rich (1996) castdoubt on its identification as being from an

42 }.A. Long, P. Vickers-Rich, K. Hirsch, E. Bray, C. Tuniz

Figure 3 A Malagassy Aepyomis egg in its native land, Madagascar (photo courtesy of Air Madagascar).

Aepyornis, yet the study of the second egg, fromCervantes, confirms its identity as also Aepyornis.

The discovery of the second Australian Aepyornisegg, from Cervantes, lends support to the driftingegg hypothesis. However, most convincing evidencecomes from the recovery of two fresh King Penguin(Aptenodytes patagonicus) eggs on Western Australianbeaches, which must have come from one of thesubantarctic islands such as the Kerguelen Islands,some 2000 km away from Australia.

The first of the penguin eggs was found about 2miles south of Augusta, close to the site of theoriginal Scott River Aepyornis egg, on January 10th1974. It was found by three beach fishermen whoplucked it at the high water mark, examined it andthrew it away behind the first sand dunes. OnJanuary 12th 1974 Geoff Lodge met with one of thefishermen, went to the site and after an hour'ssearch, and found the egg intact in the dune. Whenthe egg was blown, it was found to contain anembryo quite advanced, without any odour ofdecay. As the egg laying season for these penguinsis between late November and mid-April, the eggmu t have been transported in an advanced stageof incubation by the West Wind Drift, and wasdiscovered almost immediately after reaching theWest Australian coast. The discovery of this eggand further details pertaining to it are described byLodge (1976). The specimen is now held in theprivate collection of Mr G. Lodge at Boyup Brook,Western Australia.

A second egg of Aptenodytes patagonicus wasfound on Trigalow Beach, in Doubtful Bay Islandnear Bremer Bay on the southern coast of WesternAustralia in March 1991. This egg measures 11 cmlong and is now registered in the ornithologicalcollection of the Western Australian Museum asA2490S. This egg is also intact and was coveredwith barnacles and algae, which were easilyremoved by the finder without damage to the shellbefore it was examined by museum scientists. Theegg contained addled contents. The nearest livingcolonies for these penguins are Marion Island, theCrozets, the Kerguelen Islands and Heard Island(Figure 7). The most likely source, given the currentpatterns and proximity to Western Australia,would be the Kerguelen Islands.

Yet another egg, an Ostrich egg (Struthio camelus),was retrieved from a dredge in the Timor Sea inthe early 1990s, just south of Timor, northwest ofthe Western Australian coastline. The egg washeavily weighed down with algae, so was notactually floating at the surface of the water, butsuspended in mid-water according to its finder,who brought the egg into the Western AustralianMuseum. The egg was examined and identified asthat of an Ostrich and returned to its finder by RonJohnson of the Ornithology Department of theWestern Australian Museum (R. Johnston, personalcommunication 1996).

And still another convincing piece of evidencefavouring the rapid drifting hypothesis for the

The Cervantes egg 43

Figure 4 Thin section (radial) of the egg shell of the Cervantes egg showing the three major layers (exactly the samein Aepyornis): arrows point to the boundary between the outer layer (top left only), the continuous layer(middle) and the mammillary layer. The dark vertical line indicated by the arrow is a faint indication of oneof the pore canals (x50) (courtesy of K. Hirsch).

Aepyornis eggs comes from Betty Beach, nearManypeaks, Narrikup, Western Australia, where in1980 a float was found that had originated in SouthAfrica. The float had been released in 1977 as apart of a study of in-shore current movements.Thus, there is evidence supporting the transport ofintact fragile material, such as eggs, over longoceanic distances.

One question raised with regard to longdistance drift is the lack of marine encrustationsthat should occur on items such as eggs, if theyhad spent several months at sea. To this end, weobserve that glass floats frequently wash up on

Western Australian beaches that have barnacleson them and are soon sandblasted clean andpolished. This process could have occurred to theAepyornis eggs after they had reached shore, thusremoving the trace of marine growth. Evidencefor this is seen on the Scott River egg, whichshows one surface highly polished from winddriven sand blasting.

Although long distance rafting is certainly apossibility, another exists, and that is one of shortdistance dispersal. During the 19th and 20thcenturies it was not uncommon to find ElephantBird ggs aboard ships sailing around the world. It

44 J.A. Long, P. Vickers-Rich, K. Hirsch, E. Bray, C. Tuniz

Figure 5 Surface structure of Aepyornis eggshell. Note the long slit-like structures into which the pores open. Thistype of structure is exactly what is seen in the Cervantes egg (x20).

is possible that one or both of the eggs arrived nearAustralia aboard ship and with shipwreck endedup on Western Australian beaches, travelling onlya short distance. We note that at the location of theScott River egg, in the dunes near Augusta, therehave been no records of early shipwrecks

SAMPLE NO.: OZA095

Karl-Heintz Wrywoll, a specialist in Quaternarysedimentary deposits at the University of WesternAustralia, visited the site near Cervantes wherethe egg was found. He suggested that theCervantes egg could easily have floated in on aquite recent storm surge as it was lying not far

100

AGE cal BC/AD

aoo 300

AEPYORNIS (ELEPHA T BIRD) EGG

Figure 6 Plot of data upon which the date of the Cervantes egg was based.

The Cervantes egg 45

INDIAN OCEANMadagascar

Bay

Kerguelen Is.Crozet Is. ,-

%

~~II••lllliiilli~c~e~rv:a;n;t;,e;s%:.e:g:g~~~Aepyornis eggs

Augusta

".,_ / Bremer,~":-"'"

'':~,'''''S' Scott River

~~~.~~~ egg site

~~living colonies of King Penguins Heard Is. • Rafting route forAptenodytes patsgonicus King Penguin eggs

ANTARCTICA

Figure 7 Map showing the position of nearest living colonies of King Penguins, Aptenodytes patagoniclIs. whose eggshave also travelled by oceanic currents to end up on Western Australian beaches near Augusta (in 1976)and Bremer Bay (in 1991). Possible rafting route and sites where the two At17yomis eggs were found are alsoindicated.

above the current high tide mark. The Holocenedunes in which the egg was buried contained novisible evidence of human activity, such asshipwreck artifacts or signs of Aboriginalinfluence, such as midden remains or tools. 50,perhaps the Cervantes egg was a long distancemarine tourist.

by long distance rafting. It is still possible that itcould have floated ashore from a shipwreck, but itis most likely an overseas tourist. Both in its form,macrostructure and microstructure it is moresimilar to Aepyomis than to any of the native giantland birds in the family Dromornithidae.

CONCLUSIONS

It appears that the egg recovered from nearCervantes by three primary school children in late1992 is from the extinct Elephant Bird ofMadagascar, maxillllls. The egg has beendated at about 2000 years of age and certainlycould have reached the Western Australian coast

ACKNOWLEDG EMENTS

We thank Ron Johnstone of the WesternAustralian Museum for allowing us to examine therafted King Penguin eggs and providing invaluablediscussion on the subject of drifting eggs; John Bellfor use of the photo in Figure 1, and AirMadagascar for the use of the photo in Figure 3.We thank the referees for their helpful comments:

46

WaIter Boles, of the Australian Museum, and KenMcNamara, of the Western Australian Museum.

REFERENCES

Berger, R. Ducote, K. Robinson, K. and Waiter, H.(1975). Radiocarbon date for the largest extinct bird.Nature 258: 709.

Hirsch, K.F. and Packard, M.J. (1987). Review of fossileggs and their structure. Scanning Microscopy 1: 383­400.

Lodge, G.A (1976). King penguin egg washed ashore inWestern Australia. Westem Australian Naturalist 13:146.

Long, J.A. 1993. Eggstraordinary finds from WesternAustralia. Australian Natural History 24 (7): 6-7.

Long, A., Hendershott, R.B. and Martin, P5. (1983).Radiocarbon dating of fossil eggshell. Radiocarbon 25:533-539.

J.A. Long, P. Vickers-Rich, K. Hirsch, E. Bray, C. Tuniz

Mory, AJ. (1994). Geology of the Hill River-Green head1:200,000 sheet. Geological Survey of WesternAustralia, Explanatory Notes: 1-29.

Tuniz, C. Fink, D., Hotchkiss, M.AC., Jacobsen, G.E.,Lawson, E.M., Smith, A.A., Bird, J.R., Boldeman,J.W. (in press). The ANTARES AMS Centre at LucasHeights Research Laboratories. Radiocarbon 37.

Williams, D.L.G. and Rich, P.V. (1992). Giant fossil eggfragment from the Tertiary of Australia. Contributionsin Science, Los Angeles County Museum of NaturalHistory 26: 375-378.

Williams, D.L.G., and Rich, P.Y. (1996). Fossil eggs fromthe Tertiary and Quaternary of Australia. InP.Vickers-Rich, ].M Monaghan, R.F. Baird and T.H.Rich (eds), Vertebrate Palaeontology of Australasia,Monash Science Centre, Melbourne: 871-892.

Manuscript received 17 June 1997; accepted 4 December1997.