vegetation during the mid-Tertiary in southern North 
America. 
BoTANICAL SOURCE OF THE AMBER 
In contrast to the classical view that amber is derived 
from pines or, at least, pines and other conifers, it has 
been demonstrated on the basis of several lines of col- 
lateral evidence that the source of most of the Chiapas 
amber is the leguminous genus Hymenaea (Langenheim 
and Beck, 1965; Langenheim, 1966). This genus has 
the center of its distribution today in the Amazon Basin. 
Of the 20 species commonly recognized (Record and 
Hess, 1948), only one species,’ Hymenaea Courbaril L., 
has a wide distribution. It occurs throughout northern 
South America (Brazil, Bolivia, Colombia, Ecuador, 
Venezuela, the Guianas), along the Pacific slopes 
throughout Central America to central Mexico, and on 
most of the islands of the West Indies. Prof. Faustino 
Miranda (per. comm., 1964) identified a Hymenaea leaf- 
let in the amber which resembles both Hl. Courbaril and 
H. intermedia Ducke, the latter today restricted to the 
Amazon region. On the basis of diagnostic glandular 
morphology, the leaflet probably more closely resembles 
present-day populations of H. Courbaril than H. inter- 
media. Likewise, similarities in the infrared spectra of 
most of the Chiapas amber and of resin of modern pop- 
ulations of H. Courbaril make it appear that the amber 
was produced possibly by an ancestral population of 7. 
Courbaril. 
Although ecological data are scarce throughout its 
wide range of distribution, the senior author has ob- 
served Hymenaea Courbaril to be an important member 
* Some taxonomists also recognize Hymenaea candolleana HBK. as 
occurring in Central America. Most workers, in Mexico at least (F. 
Miranda, per. comm, 1964), think that H. candolleana is at best a 
variety of H. Courbaril and does not warrant specific designation. 
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