Dinosaur eggsl and babies

Dinosaur eggsl and babies

BOOK REVIEWS Palaeoparental care Dinosaur Eggs and Babies edited by K. Carpenter, K.F. Hirsch and J.R. Homer CambridgeUniversity Press, 1994. 560.0...

135KB Sizes 0 Downloads 58 Views

BOOK

REVIEWS

Palaeoparental care Dinosaur Eggs and Babies edited by K. Carpenter, K.F. Hirsch and J.R. Homer

CambridgeUniversity Press, 1994. 560.00hbk (xiv + 372 pages) ISBN0 52144342 3

T’

hrs superb compilation volume is the fourth m an irregular run of dinosaurrelated books published over the past ten years by CambridgeUniversityPress:dine saur origins,dinosaursystematics,dinosaur tracks,and shortly, the smallvertebratesof the Age of the Dinosaurs.Eachvolume has containeda large number of generallywelledited contributions - 24 chapters in the presentvolume- at a reasonableprice, and all of them so far have goneinto paperback. The covers have been exciting, and Greg Paul’sdrawing of a baby titanosaur on the present book is superb. Symposiumand compilationvolumesdeserveto be produced in an attractive fashionand sold widely,and the publishingpolicy of Cambridgeis admirable in the caseof thesebooks,which could readily be hidden away in dull covers and priced at a high level. Dinosaureggswere first reported from the LateCretaceousof Francein 1859,and a possibleclutch of eggs came to light from the Middle Jurassicof Englandin the same year. The French and English discoveries were overshadowedby the publicity generated around the finding of nests of eggs of the armoured dinosaur Protocerutops in Mongoliaby AmericanMuseumexpeditions in the 1920s.The Mongolianeggs,and associatedskeletonsof babiesand juveniles, were widely promoted in the 1920sand 1930s and formed the basis of exhibition materialsthat were cast and widely circulated, as well as paintings by influential artists.Sincethen, dinosaureggshave been foundin the USA,Canada,China,Kazakhstan, Uzbekistan,India, Tanzania,South Africa, Brazil,Uruguay,Spain,PortugalandRomania. Someof the most recentdiscoveriesinclude astonishing dinosaur eggs from Chinese Mongolia that include embryos, and perhaps belong to a number of different taxa: the askingprice is millionsof dollars! Dinosaur eggs are studied by light microscopy, polarized light microscopy and scanning electron microscopy. The crystalline structure of the eggshell,patterns of pore tubes, and externalornamentationall vary among taxa, although the features of manyeggshellsare similarto thoseof birds, direct descendantsof the theropod din+ saurs. Dinosaur eggshellsare made from crystallinecalcite(CaCO,),and someinvestigators havereported the presenceof original organic material, proteins and amino 48

acids:it is not clear,however,whethersome ~implications.The remainingchapters deal of the latter might be the resultsof bacterial with case studies, presentingdescriptions decay. of new sites, and investigationsof eggsand Someof the most exciting recent work babiesfrom specific locations.The editors in the study of dinosaur eggshas been the have done a splendid job of maintaininga investigatfonof nests. Jack Homer, one of high standard of presentationthroughout, the editors,has found evidencein Montana, and in assisting those authors for whom USA,that some baby dinosaurs remained Englishis a secondlanguage. in the nest where they were fed by parents Michael J. Benton and older siblings (cf. nidicolous birds), whereas others fled the nest and began to Dept of Geology, Umverslty of Bristol. feedright away(cf.nidifugousbirds).Parents Bristol. UK ES8 1RJ of somedinosaur speciesat least,returned to favourednestinggroundsyear after year, as evidencedby accumulationsof identical neststhrough manylayersof sediment. Nests were scraped in the soil, and a shallow bowl was created into which the mother laid 20 or more eggsin regular circular patterns. She covered the eggs with vegetation,and may have urinated on top, to stimulatedecompositionand the develop Everglades: ment of a compost-likeincubatingenvironment.Parentsand siblingsremainedaround Ecosystem and its Restoration edited by S. M. Davis and J. C Ogden the nests to assistat hatchingtime, as indicated by the finds of skeletonsof one dinoSt Lucie Press, 1994. saur species at all developmentalstages f80.00 hbk (xv + 826 oaees) scatteredaround the site. ISBN0 9634030i 8- ’ Dinosaur babies have been reported from many parts of the world, sometimesin uergladesis an extraordinary 825.page associationwith eggsand nests,sometimes compendium of scientific information, isolated. These all show juvenile features, and I commendthe editors for bringing it not only small size, but also incompletely to publication. The book reviews various ossified bones and allometric dispro- componentsand driving forcesof the ‘River portions, such as extra-largeheads, eyes of Grass’,providing local researcherswith and limb joints. Baby dinosaurs were just essentialbackgrounddata. For those of us who work elsewhere,it opensthe door to an like puppies. The small size of dinosaur eggs and internationallyrecognizedwetland and the babiesis important. Eventhe largestsauro controversies surrounding its life blood: pod dinosaursproducedeggsthat were less water. Unlike many collections of papers, than 250m m long;presumablythe eggswere this one has a specific common purpose not in proportion to adult size becausethe understandinghow the Evergladesecosyseggshellwould then be too thick for the tem (in Florfda,USA)works so that its biodibaby to escape.It is likely that the tiny juv- versity can be sustainedand its functions enile dinosaursgrew rapidly to reach adult restored. size,perhapsin 5-lo years,rather than over The book speaksto a wide audience,be a prolonged time span, and with human- ginning with an ecologyprimer, moving to style growth rates. Rapid growth rates in geologicaland land-use history, peat fordinosaursimply accessto good nutrition, a mation,vegetationand fauna,and concludfavourableclimate,elevatedmetabolicrates, ing with restoration goalsand issues.There and the ability to store and mobilize phos- are interesting accounts of the problems phorus and calcium in the bones. All the of cattle ranching (copper deficiency),the histologicalevidencefrom dinosaur bones shift to sugar production when Castrotook supports these contentions, and the view over Cuba,the history and impactsof exotic that dinosaurs had active metabolisms, speciesintroductions (especiallythe paperalthoughthis does not imply full avian-style bark tree, Melaleuca guinquenervia), the endothermy. plight of wading birds (90% reduction in The 24 chapters are presented by 49 nesting) and panthers (an estimated50 reauthors,representing13countries.It is credi- main),the endangeredbird (snail kite) that table that the coverageis truly global,with specializeson apple snails,how expanding 16 authors from the USA,nine from France, cattails affect snail habitat, how plants and seven from India, five from Romaniaand animalsrespondto wet and dry years,how three from Canada.Thereare superbreview reductions in water quantity and quality chapters on the distribution of dinosaur (especiallyphosphorusrun-off) affect both eggsand nests, dinosaur nesting patterns, the Evergladesand Florida Bay, and how the structureof eggshells, developmentalpat- this and other major water diversion proterns of dinosaur babies, and behavfoural gramshaveforever modifiedcoastalwaters

Whole-ecosystem change following hydrologic modification

E

TREE uol.

10, no

I January

1995